🧬 ICD-10 CM C32.1 — Malignant Neoplasm of Supraglottis
Billable Code Confirmed
ICD-10 CM C32.1 is a valid, fully billable 4-character ICD-10-CM code effective FY2026, assigned to malignant neoplasm of the supraglottic larynx — the compartment extending from the tip of the epiglottis superiorly to the laryngeal ventricles inferiorly, excluding the true vocal cords. The code is terminal at the 4th character level; no 5th or 6th character extensions exist for supraglottic laryngeal malignancy, and no additional specificity is available or required beyond what C32.1 captures. Laterality is not coded for C32.1 because the larynx is an anatomically midline organ whose subsites are defined by vertical compartment (supraglottis, glottis, subglottis) rather than left-right orientation, making this code complete without a laterality extension.1
Non-Billable Parent Code
The parent code C32 (Malignant neoplasm of larynx) is a non-billable 3-character category code that cannot be submitted on a claim; it requires a 4th character to achieve billable specificity. Coders must assign one of the terminal 4th-character codes — C32.1 for supraglottis, C32.0 for glottis, C32.2 for subglottis, C32.3 for laryngeal cartilage, C32.8 for overlapping sites, or C32.9 for larynx unspecified — based on documentation of the involved subsite. Defaulting to C32 without the required 4th character will result in claim rejection and may trigger a medical necessity audit; the parent code should never appear on a claim or UB-04 in any field position.1
Clinical Context
The supraglottis has rich bilateral lymphatic drainage that produces early and often bilateral cervical nodal metastasis — a hallmark that distinguishes supraglottic cancer from glottic cancer (C32.0) and that makes accurate subsite documentation critical for both clinical management and coding. Unlike glottic tumors, which affect the voice early and are discovered at lower stage, supraglottic cancers frequently remain clinically silent until they reach T3-T4 or N2-N3 stage; presenting symptoms are typically dysphagia, throat fullness, referred otalgia, and globus sensation rather than hoarseness, which appears only when the glottis is invaded by extension. The epiglottis is a divided coding structure — the posterior (laryngeal) surface and epiglottis NOS are included under C32.1, while the anterior (lingual) surface maps exclusively to C10.1 (oropharynx); when documentation does not specify which epiglottic surface is involved, a CDI query is required before finalizing code assignment.1,2,3
Code Classification
ICD-10 CM C32.1 is a principal or secondary ICD-10-CM diagnosis code representing a confirmed malignant neoplasm — it is not a procedure code, a screening code, or a symptom code, and it must not be assigned on the basis of imaging findings alone without provider confirmation of malignancy. Per ICD-10-CM guideline Section I.C.2, inpatient coders may code the confirmed diagnosis documented in the discharge summary even when admission documentation used “suspected” or “rule-out” language; if the pathology result is returned and the attending documents confirmed malignancy at discharge, C32.1 is correct for the admission.1,4
🔍 Code Description
ICD-10 CM C32.1 captures all malignant neoplasms arising from the supraglottic laryngeal compartment, which anatomically encompasses the epiglottis (suprahyoid and infrahyoid portions, posterior surface), the aryepiglottic folds (laryngeal aspect), the false vocal cords (ventricular folds), the laryngeal ventricles, the ventricular bands, and the arytenoids.1,2 The supraglottis is developmentally distinct from the glottis and subglottis — it arises from the buccopharyngeal anlage rather than the tracheopulmonary anlage — a fact that explains its rich bilateral lymphatic drainage, its tendency toward early bilateral cervical nodal spread, and its typically advanced clinical stage at presentation compared to glottic carcinoma (C32.0).3 Squamous cell carcinoma (SCC) accounts for more than 95% of supraglottic malignancies; less common histologic variants include large-cell neuroendocrine carcinoma, small-cell neuroendocrine carcinoma, minor salivary gland carcinomas, lymphomas, and sarcomas — neuroendocrine carcinoid tumors are specifically excluded from C32.1 and coded separately to C7A.092.2,3 Tobacco use and alcohol consumption are the primary modifiable risk factors, and C32.1 carries a mandatory use additional code instruction requiring capture of tobacco status (F17.210-F17.219 for nicotine dependence, Z87.891 for history of tobacco dependence, or Z72.0 for tobacco use), alcohol use or dependence (F10.-), occupational tobacco smoke exposure (Z57.31), and environmental tobacco smoke exposure (Z77.110) whenever these are documented.1,4
Accurate assignment of C32.1 requires explicit subsite documentation in the operative report, pathology report, or attending physician’s diagnostic statement; chart language that simply reads “laryngeal cancer,” “larynx SCC,” or “carcinoma of the larynx” without specifying the supraglottis, glottis, or subglottis drives assignment of C32.9 (larynx, unspecified) and should trigger a CDI query before code finalization.1,4 ICD-10-CM does not encode AJCC/TNM stage within C32.1 — staging is conveyed through pathology and radiology reports and is not directly represented by the diagnosis code — but secondary codes for confirmed regional lymph node metastasis (C77.0) and distant metastases (C78.01, C78.02, C79.89) must be assigned when documented to ensure complete clinical capture and accurate HCC hierarchy mapping.1,4 Approximately 35-55% of patients with supraglottic cancer present with cervical nodal involvement at initial diagnosis, making C77.0 one of the most consistently applicable additional codes for inpatient admissions carrying C32.1 as the principal diagnosis.2,3 Treatment modalities include total laryngectomy, supraglottic partial laryngectomy, transoral laser microsurgery, concurrent chemoradiation, and induction chemotherapy — each admission type (surgical, chemotherapy, radiation) has distinct PDx sequencing requirements that materially affect DRG assignment and reimbursement.1,7,8
🌳 Code Tree / Hierarchy
C30-C39 Malignant neoplasms of respiratory and intrathoracic organs ❌ Non-billable block
│
├── C30 Malignant neoplasm of nasal cavity and middle ear ❌ Non-billable
│
├── C31 Malignant neoplasm of accessory sinuses ❌ Non-billable
│
├── C32 Malignant neoplasm of larynx ❌ Non-billable parent — requires 4th character
│ │
│ ├── C32.0 Malignant neoplasm of glottis ✅ Billable
│ ├── ▶▶ C32.1 ◀◀ Malignant neoplasm of supraglottis ← THIS CODE ✅ Billable
│ ├── C32.2 Malignant neoplasm of subglottis ✅ Billable
│ ├── C32.3 Malignant neoplasm of laryngeal cartilage ✅ Billable
│ ├── C32.8 Malignant neoplasm of overlapping sites of larynx ✅ Billable
│ └── C32.9 Malignant neoplasm of larynx, unspecified ✅ Billable
│
├── [[C33]] Malignant neoplasm of trachea ✅ Billable
│
└── C34 Malignant neoplasm of bronchus and lung ❌ Non-billable — requires 4th/5th characters
The One Character That Changes Everything — C32.1 vs. C32.0 vs. C32.9
The difference between C32.0 (glottis), C32.1 (supraglottis), and C32.9 (unspecified) is a single character that carries significant downstream consequences: subsite specification drives HCC tier accuracy, supports clinical documentation integrity, aligns with tumor registry requirements, and determines whether a CDI query is needed. Defaulting to C32.9 when subsite documentation exists in the operative or pathology report is a compliance failure, not a conservative coding choice.
Transglottic Tumors — When C32.1 Is Not the Right Code
When a single laryngeal tumor spans two or more contiguous subsites — for example, a mass involving both the supraglottis and the glottis (transglottic carcinoma) — the correct code is C32.8 (Malignant neoplasm of overlapping sites of larynx), not C32.1 alone. The overlapping site code should be used whenever the operative or pathology report documents extension across subsite boundaries; this distinction is clinically meaningful for staging purposes and should be flagged in CDI review.
✅ Includes
- Aryepiglottic fold or interarytenoid fold, laryngeal aspect — refers specifically to the laryngeal (posterior) surface of the aryepiglottic fold; the hypopharyngeal aspect of the same anatomical structure maps to C13.1 and is not included here.1
- Epiglottis NOS (suprahyoid portion, posterior/laryngeal surface) — when documentation simply states “epiglottis” without specifying surface, C32.1 applies per the Includes note; however, when the operative or pathology report specifies the anterior (lingual) surface, the code is C10.1 (oropharynx) and a CDI query is required in ambiguous cases.1
- Extrinsic larynx — refers to the extrinsic muscles and supraglottic soft tissue structures within the laryngeal compartment; documentation of extrinsic laryngeal involvement confirms supraglottic subsite and supports C32.1 assignment.1
- False vocal cord (ventricular fold) — the false cords are a defining supraglottic structure; documentation of false cord involvement is pathognomonic for supraglottic subsite and provides strong support for C32.1 over C32.9.1
- Supraglottic portion of aryepiglottic fold — the laryngeal-aspect supraglottic fold component; coders must confirm from the operative report that this is the laryngeal aspect and not the hypopharyngeal aspect coded to [[C13.1]].1
- Ventricular bands — a clinical synonym for false vocal cords; documentation of ventricular band tumor in the operative or pathology report confirms supraglottic subsite and is sufficient to assign C32.1 without an additional query.1
- Use additional code required: tobacco dependence (F17.210-F17.219), tobacco use (Z72.0), history of tobacco dependence (Z87.891), alcohol abuse/dependence (F10.-), environmental tobacco smoke (Z77.110), occupational tobacco smoke (Z57.31) — these must be coded whenever documented and are not optional.1
❌ Excludes
Excludes 1
- ICD-10 CM C10.1 — Malignant neoplasm of anterior surface of epiglottis: The anterior (lingual) surface of the epiglottis is an oropharyngeal structure coded to C10.1, not to C32.1, and these codes are mutually exclusive for a single tumor at a single surface — a laryngeal posterior-surface epiglottic tumor (C32.1) and a lingual anterior-surface epiglottic tumor (C10.1) cannot both be assigned for the same lesion. The distinction is anatomically and clinically meaningful: C10.1 carries oropharyngeal cancer classification with different tumor board, staging, and treatment protocol implications than C32.1, and misassignment between the two codes can affect MDC assignment, tumor registry reporting, and oncology-specific quality metrics. When operative or pathology documentation refers only to “epiglottis” or “epiglottic cancer” without specifying surface, C32.1 applies per the ICD-10-CM Includes note (epiglottis NOS), but when there is any indication of lingual surface involvement, a CDI query confirming surface location is mandatory before finalizing the code.1,2,3
Most Common Excludes 1 Error — Epiglottis Surface Assignment
The most frequent coding error in this family is assigning C32.1 to any epiglottic malignancy without verifying surface location — when an ENT surgeon’s note or pathology report documents “posterior epiglottic SCC” or “laryngeal surface epiglottis,” C32.1 is correct; when it documents “lingual epiglottis,” “anterior epiglottis,” or “epiglottis, vallecula aspect,” C10.1 is correct. Coders who do not review the operative description or pathology localization and default to C32.1 for all epiglottic tumors will produce systematic miscoding that is particularly likely to surface in tumor registry audits and head-and-neck oncology quality reviews.1,2,3
Excludes 2
- ICD-10 CM C7A.092 — Malignant carcinoid tumor of the larynx: This code applies when a neuroendocrine carcinoid tumor (typical or atypical carcinoid) arises from the larynx; it is separately codeable if a synchronous non-carcinoid malignancy also exists at a distinct laryngeal site, but in clinical practice a primary laryngeal carcinoid is coded exclusively to C7A.092 rather than C32.1. The critical histologic distinction is that large-cell neuroendocrine carcinoma and small-cell neuroendocrine carcinoma of the larynx are NOT carcinoid tumors under ICD-10-CM convention and are correctly coded to C32.1, while typical and atypical carcinoid neoplasms belong to C7A.092 — this requires pathology-report review to confirm tumor classification before making the assignment.1,2
📋 Clinical Overview
Supraglottic vs. Glottic vs. Subglottic — The Laryngeal Subsite Distinction
The three laryngeal compartments differ fundamentally in lymphatic drainage, symptom onset, stage at presentation, and treatment philosophy, and these clinical differences directly inform why accurate subsite coding matters beyond mere specificity compliance. Supraglottic cancer (C32.1) is characterized by silent early growth due to the absence of voice involvement, bilateral lymphatic drainage producing early N+ disease in 35-55% of patients, and a predominance of advanced-stage presentation; glottic cancer (C32.0) presents early because even small glottic tumors cause hoarseness, which brings patients to otolaryngologists at T1-T2 stage; subglottic cancer (C32.2) is rare as a primary site and typically presents with airway obstruction at advanced stage.2,3
| Feature | C32.1 Supraglottis | C32.0 Glottis | C32.2 Subglottis |
|---|---|---|---|
| Anatomic Boundary | Epiglottis tip to (above) true vocal cords — includes epiglottis, aryepiglottic folds, false cords, laryngeal ventricles | True vocal cords, anterior commissure, posterior commissure | Below true cords to inferior border of cricoid cartilage |
| Lymphatic Drainage | Rich bilateral drainage — N+ in 35-55% at presentation; bilateral N+ common | Sparse — N+ in <5% at T1-T2; risk rises with transglottic extension | Rich bilateral drainage — N+ in 40-65%; bilateral involvement common |
| Earliest Symptom | Dysphagia, globus, referred otalgia, throat fullness — hoarseness is LATE, appears only with glottic extension | Hoarseness — the hallmark early symptom; voice change at T1 stage | Progressive airway obstruction, stridor, dyspnea; hoarseness is late |
| Typical Stage at Diagnosis | Advanced (T3-T4, N2-N3) in majority of cases due to symptom silence | Earlier stage (T1-T2) in majority due to early voice change prompting workup | Advanced stage typical; primary subglottic SCC is rare (<5% of laryngeal cancers) |
| Primary Treatment | Supraglottic laryngectomy ± neck dissection, total laryngectomy, concurrent CRT, or TLM | Radiation (early stage), cordectomy, partial laryngectomy, CRT (advanced) | Total laryngectomy with bilateral neck dissection, CRT |
| CDI Priority | Subsite documentation + nodal status + malnutrition + tobacco/alcohol use codes | Subsite documentation + cord mobility status + tobacco/alcohol | Subsite confirmation — “subglottis” must appear explicitly; query if absent |
CDI Trigger — Laryngeal Subsite Documentation
The most impactful CDI query for any laryngeal cancer admission is subsite confirmation: when an H&P, operative report, or discharge summary documents “laryngeal cancer,” “larynx SCC,” or “carcinoma of the larynx” without specifying supraglottis, glottis, or subglottis, the coder must query the attending otolaryngologist before assigning C32.1 and cannot default to C32.9 if subsite information is available elsewhere in the chart. The secondary CDI priority for C32.1 admissions is malnutrition severity documentation — aspiration-related dysphagia and cancer cachexia frequently produce clinically significant malnutrition that qualifies as a CC or MCC, and a dietitian’s documented malnutrition assessment combined with attending attestation can elevate DRG tier assignment materially.1,4
Manifestations and Symptom Burden
- Dysphagia — among the earliest presenting symptoms due to epiglottic or aryepiglottic fold involvement disrupting the coordinated swallowing mechanism; document as R13.10 (dysphagia, unspecified) or specify phase with R13.11 (oral phase), R13.12 (oropharyngeal phase), or R13.19 (other dysphagia) when the swallowing evaluation documents the phase of dysfunction.2
- Referred otalgia — pain referred to the ipsilateral ear via the vagus nerve (Arnold’s nerve) is a classic and frequently underappreciated symptom of supraglottic and hypopharyngeal malignancy; document as H92.01 (right ear) or H92.02 (left ear) when laterality is specified, or H92.09 when unspecified — this symptom drives many initial referrals and may be the presenting complaint in cases where the primary tumor is not yet visualized.2,3
- Cervical lymphadenopathy with confirmed nodal metastasis — when nodal metastases are confirmed by pathology, FNA cytology, or clinical documentation, assign C77.0 (secondary malignant neoplasm of lymph nodes of head, face, and neck) as an additional diagnosis; this code also activates HCC 7 hierarchy supersession when combined with distant metastatic codes.1,4
- Respiratory compromise and stridor — airway obstruction occurs when the tumor achieves significant bulk or subglottic extension; when respiratory failure is explicitly documented by the attending, assign J96.01 (acute respiratory failure with hypoxia) or J96.11 (chronic respiratory failure with hypoxia) as appropriate — these qualify as MCCs and produce significant DRG tier uplift.2
- Cancer-related malnutrition — dysphagia-driven and cachexia-driven malnutrition is nearly universal in advanced supraglottic cancer; E43 (unspecified severe malnutrition) qualifies as an MCC and E44.0 (moderate protein-calorie malnutrition) qualifies as a CC — attending attestation of malnutrition severity combined with dietitian documentation supports code assignment and represents one of the highest-yield CDI targets in laryngeal cancer inpatient admissions.1,4
Manifestation Coding Guidance
Per ICD-10-CM guideline Section I.C.2.d, signs and symptoms that are integral to a confirmed malignancy and routinely associated with the disease process — mild anorexia, generalized fatigue, or incidental weight loss — are generally not coded separately in the inpatient setting when they do not provide additional clinical information. However, complications that represent independently significant comorbidities demanding additional resources — clinician-documented malnutrition, aspiration pneumonia (J69.0), respiratory failure, or sepsis — are separately coded and must be captured to reflect accurate clinical complexity and ensure correct DRG tier assignment. The distinction between “expected manifestation” and “separately significant complication” in supraglottic cancer is high-yield CDI territory and should be part of every concurrent review checklist for these admissions.1,4
💰 HCC Risk Adjustment
| Field | Value |
|---|---|
| HCC Category (CMS-HCC V28) | HCC 8 — Lung and Other Severe Cancers ⚠️ Verify against current CMS V28 crosswalk |
| Model Year | CMS-HCC V28 (sole operative model effective calendar year 2024) |
| V28 Cancer Hierarchy | HCC 7 (Metastatic) > HCC 8 (Severe Cancers) > HCC 9 (Lymphoma/Other) > HCC 10 (Breast/Prostate/CRC) |
| Annual Recapture Required | ✅ Yes — active malignancy must be documented and coded at minimum once per calendar year |
| Hierarchy Override | HCC 7 supersedes HCC 8 when distant metastases are confirmed and coded (C77.0, C78.01, C78.02, C79.89) |
| Payer Relevance | Medicare Advantage, ACA Marketplace plans, Medicaid managed care |
| RAF Weight | ⚠️ Verify against current CMS-HCC V28 ratebook — do not use V24 RAF values |
ICD-10 CM C32.1 maps to HCC 8 (Lung and Other Severe Cancers) under CMS-HCC V28, reflecting the clinical severity, high resource utilization, and treatment intensity associated with supraglottic laryngeal malignancy — a cancer that frequently requires total laryngectomy, bilateral neck dissection, concurrent chemoradiation, and long-term swallowing rehabilitation.5,6 HCC 8 sits in the upper tier of the V28 cancer hierarchy immediately below HCC 7, and the RAF weight for HCC 8 is substantial relative to mid- and lower-tier cancer categories; when a patient also has confirmed distant metastatic disease, only HCC 7 is counted in the hierarchy — making accurate metastatic status documentation and coding critical for RAF integrity.5,6 Annual recapture of C32.1 for patients with active laryngeal cancer is clinically and financially essential: the diagnosis must be documented by a provider in a face-to-face encounter at least once per calendar year to contribute to the plan’s risk score for that year, and failure to recapture results in loss of the full HCC 8 contribution.5,6 CDI programs should ensure that providers use explicit language confirming active malignancy and current treatment status — such as “active malignant neoplasm of the supraglottis, currently receiving concurrent chemoradiation” — rather than relying on historical problem list documentation, which may not meet payer recapture standards. ⚠️ Verify HCC category number and RAF weight against the current CMS-published diagnosis-to-HCC crosswalk and V28 ratebook before finalizing any risk adjustment work product.5,6
🏥 MS-DRG Assignment
| Field | Value |
|---|---|
| MDC | MDC 03 — Diseases and Disorders of the Ear, Nose, Mouth and Throat |
| DRG with MCC | DRG 011 — Tracheostomy for Face, Mouth & Neck Diagnoses or Laryngectomy with MCC |
| DRG with CC | DRG 012 — Tracheostomy for Face, Mouth & Neck Diagnoses or Laryngectomy with CC |
| DRG without CC/MCC | DRG 013 — Tracheostomy for Face, Mouth & Neck Diagnoses or Laryngectomy without CC/MCC |
| Alternate Surgical DRGs | DRG 148/149/150 — Major Head and Neck Procedures with MCC/CC/without CC-MCC (partial laryngectomy, neck dissection without laryngectomy, TLM) |
| Chemotherapy DRGs | DRG 847/848/849 — Chemotherapy with/without Acute Leukemia or MCC (Z51.11 as PDx) |
| DRG Weights | ⚠️ Verify against current CMS IPPS Final Rule and applicable MS-DRG grouper version |
When C32.1 is the principal diagnosis and a total or supraglottic laryngectomy (0CTS0ZZ or 0CBS0ZZ) is the principal ICD-10-PCS procedure, the case groups to MDC 03 surgical partition and DRGs 011-013 (Tracheostomy for Face, Mouth & Neck Diagnoses or Laryngectomy), which carry among the highest relative weights in MDC 03 given the complexity, operative time, and postoperative resource intensity of laryngeal resection.7,8 CC/MCC tier is the primary reimbursement driver within this DRG family — common MCCs in laryngeal cancer surgical admissions include respiratory failure (J96.01, J96.11), severe malnutrition (E43), and sepsis (A41.9); common CCs include aspiration pneumonia (J69.0), dysphagia (R13.19), and moderate malnutrition (E44.0) — and failure to capture any one of these can represent a DRG tier downgrade with significant reimbursement impact, making concurrent CDI review of these admissions a high-priority function.7,8 When the admission involves a partial laryngectomy (supraglottic laryngectomy — 0CBS0ZZ), a major neck dissection without total laryngectomy, or a transoral laser excision, the case may group to DRG 148/149/150 (Major Head and Neck Procedures) rather than DRG 011/012/013, and grouper output should be verified for each distinct procedure type to confirm tier assignment. For admissions where chemotherapy is the sole purpose, Z51.11 is sequenced as PDx per ICD-10-CM guideline I.C.2.e, C32.1 is coded as an additional diagnosis, and the case moves from MDC 03 to MDC 17 DRG 847/848/849 — this PDx sequencing distinction is among the most commonly audited oncology coding findings, and reversing the sequence has direct DRG and reimbursement consequences. ⚠️ Verify all DRG weights and grouper assignments against the current CMS IPPS Final Rule and applicable MS-DRG grouper version before submission.7,8
🔗 Related ICD-10-CM Codes
Laryngeal and Adjacent Site Malignancies
| Code | Description | Clinical Distinction |
|---|---|---|
| C32.0 | Malignant neoplasm of glottis | True vocal cords, anterior and posterior commissures; presents early with hoarseness; low initial nodal risk; single most important sibling code for CDI subsite differentiation |
| C32.2 | Malignant neoplasm of subglottis | Below true cords to inferior cricoid border; rare as primary site (<5% of laryngeal SCC); high bilateral nodal risk similar to C32.1; frequently results from inferior extension of another laryngeal subsite tumor |
| C32.3 | Malignant neoplasm of laryngeal cartilage | Thyroid, cricoid, or arytenoid cartilage primary; typically arises in context of cartilage invasion from an adjacent subsite — assign C32.8 when a single tumor overlaps a subsite and cartilage |
| C32.8 | Malignant neoplasm of overlapping sites of larynx | Single tumor crossing two or more contiguous laryngeal subsites (e.g., transglottic carcinoma spanning supraglottis and glottis); correct code when a tumor cannot be attributed to a single subsite — do not assign C32.1 and C32.0 individually for one transglottic lesion |
| C32.9 | Malignant neoplasm of larynx, unspecified | Default code only after CDI query fails to produce subsite documentation; must not be used as a routine fallback when chart review would yield the specific subsite |
| C10.1 | Malignant neoplasm of anterior surface of epiglottis | Lingual/oropharyngeal epiglottis surface — mutually exclusive with C32.1 for a single epiglottic tumor; different anatomical classification, staging system reference, and treatment pathway |
| C13.1 | Malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect | Hypopharyngeal aspect of the aryepiglottic fold — distinct from the laryngeal aspect coded under C32.1; when documentation does not specify laryngeal vs. hypopharyngeal aspect, a CDI query is required |
Regional, Distant, and Post-Treatment Codes
| Code | Description | Clinical Distinction |
|---|---|---|
| C77.0 | Secondary malignant neoplasm of lymph nodes of head, face, and neck | Confirmed cervical nodal metastasis — one of the most consistently applicable additional codes in supraglottic cancer given the 35-55% N+ rate at presentation; triggers HCC 7 hierarchy consideration when combined with distant metastasis codes |
| C78.01 | Secondary malignant neoplasm of right lung | Pulmonary metastasis, right — when confirmed, triggers HCC 7 (Metastatic Cancer) in V28, superseding HCC 8 and substantially increasing RAF weight |
| C78.02 | Secondary malignant neoplasm of left lung | Pulmonary metastasis, left — same HCC hierarchy implications as C78.01; assign the specific laterality code when imaging or pathology report identifies the side |
| C79.89 | Secondary malignant neoplasm of other specified sites | Distant metastasis not covered by more specific secondary malignancy codes; triggers HCC 7 when assigned alongside C32.1 |
| Z85.21 | Personal history of malignant neoplasm of larynx | Post-treatment surveillance code — replaces C32.1 only after documented completion of all treatment with no evidence of active disease; never use Z85.21 alone as PDx when active or recurrent malignancy is confirmed |
🛠️ Commonly Associated CPT Codes
| CPT Code | Description | Billing Notes |
|---|---|---|
| 31360 | Laryngectomy; total, without radical neck dissection | Total laryngectomy without neck dissection; the primary CPT code for total laryngectomy admission; maps to ICD-10-PCS 0CTS0ZZ; global period 090 days; principal procedure driving DRG 011/012/013 tier when C32.1 is PDx |
| 31365 | Laryngectomy; total, with radical neck dissection | Total laryngectomy combined with radical neck dissection performed en bloc; report 31365 rather than 31360 plus a separate neck dissection code when the two procedures are performed together; verify NCCI edits before unbundling neck dissection from laryngectomy |
| 31367 | Partial laryngectomy (hemilaryngectomy); subtotal supraglottic, without radical neck dissection | The CPT code most directly corresponding to the surgical procedure for C32.1 — supraglottic laryngectomy preserving the true vocal cords; maps to ICD-10-PCS 0CBS0ZZ; assign only when documentation confirms subtotal supraglottic resection with true cord preservation and functional laryngeal continuity |
| 31368 | Partial laryngectomy (hemilaryngectomy); subtotal supraglottic, with radical neck dissection | Supraglottic laryngectomy combined with radical neck dissection; 31368 is preferred over 31367 plus a separate neck dissection code when both procedures are performed in the same operative session; review NCCI edits for the specific pair before separating |
| 31576 | Laryngoscopy, flexible; with biopsy(ies) | Flexible laryngoscopy with tissue biopsy — typically the initial diagnostic procedure that confirms C32.1; global period 000; report with modifier RT or LT when applicable to identify the biopsied side; maps to ICD-10-PCS 0CBS8ZX in the inpatient setting |
| 31541 | Laryngoscopy, operative, with operating microscope or telescope; with excision of tumor or lesion, or removal of foreign body | Direct operative laryngoscopy with tumor excision under microscope; used for transoral laser microsurgery (TLM) of supraglottic lesions; maps to ICD-10-PCS 0CBS8ZZ; report with C32.1 as primary diagnosis when TLM is the definitive treatment for supraglottic malignancy |
NCCI Bundling Considerations
When a total laryngectomy (31360 or 31365) is performed, NCCI edits bundle concurrent procedures routinely performed as part of laryngectomy — including tracheostomy creation, cricopharyngeal myotomy, and pharyngeal closure — and these component services should not be separately reported without independent documentation supporting a truly distinct service with a modifier such as -59 or -XS/-XU.9 When supraglottic laryngectomy (31367) is performed in the same session as a neck dissection, the code pair relationship must be evaluated against current NCCI edits — 31368 bundles radical neck dissection into a single code, while 31367 does not, but separately reporting a neck dissection alongside 31367 requires verification that the edit pair allows separate reporting and that modifier -59 documentation criteria are met.9 Diagnostic laryngoscopy codes are typically bundled with operative laryngoscopy codes when performed in the same session at the same site; do not separately report a diagnostic flexible laryngoscopy and a therapeutic direct laryngoscopy on the same date without confirming NCCI logic permits separate reporting, since unbundling these codes without appropriate modifier support creates significant audit exposure for oncologic head and neck surgery claims.9
🔬 ICD-10-PCS Crosswalk
| PCS Code | Full Description | Applicable Procedure |
|---|---|---|
0CTS0ZZ | Resection of Larynx, Open Approach | Total laryngectomy — complete removal of the entire larynx; maps to CPT 31360/31365; principal procedure driving DRG 011/012/013; root operation Resection (T) selected because the entire body part is removed per PCS guideline B3.8 |
0CBS0ZZ | Excision of Larynx, Open Approach | Partial/supraglottic laryngectomy — removal of supraglottic structures preserving functional residual laryngeal tissue; maps to CPT 31367/31368; qualifier Z (No Qualifier) confirms therapeutic, not diagnostic, intent |
0CBS8ZX | Excision of Larynx, Via Natural or Artificial Opening Endoscopic, Diagnostic | Flexible or direct laryngoscopy with biopsy — endoscopic approach, diagnostic qualifier X required per PCS guideline B3.4a when the procedure is solely to obtain a tissue specimen for pathological diagnosis; maps to CPT 31576 |
0CBS8ZZ | Excision of Larynx, Via Natural or Artificial Opening Endoscopic | Transoral endoscopic excision of laryngeal tumor with therapeutic intent — transoral laser microsurgery (TLM) or endoscopic tumor excision; qualifier Z (No Qualifier) confirms therapeutic purpose; maps to CPT 31541; distinct from 0CBS8ZX by qualifier only |
PCS Character Analysis — 0CTS0ZZ
| Position | Character | Value | Definition |
|---|---|---|---|
| 1 | Section | 0 | Medical and Surgical — the section that encompasses all definitive surgical procedures performed on body organs and tissues, including extirpation, resection, and reconstruction |
| 2 | Body System | C | Mouth and Throat — the PCS body system that includes the larynx, pharynx, epiglottis, vocal cords, salivary glands, tongue, and oral cavity; the larynx resides in body system C (Mouth and Throat), not body system B (Respiratory System), which is a common lookup error |
| 3 | Root Operation | T | Resection — cutting out or off, without replacement, all of a body part; Resection is selected over Excision (B) when the entirety of the laryngeal body part is removed, even when clinical documentation uses “partial laryngectomy” language, as long as the complete anatomically defined body part (larynx, body part S) is functionally resected |
| 4 | Body Part | S | Larynx — the specific body part value for the larynx within the Mouth and Throat system; this single body part value encompasses the supraglottis, glottis, subglottis, and all laryngeal cartilaginous and soft tissue structures as a unified coding unit; the epiglottis (body part R) and vocal cords (T = right, V = left) are separate body part values used when those structures alone are the target |
| 5 | Approach | 0 | Open — direct visualization through an external cervical incision; the standard surgical approach for total laryngectomy; transoral endoscopic procedures use approach 8 (Via Natural or Artificial Opening Endoscopic) |
| 6 | Device | Z | No Device — no implant or device is left in the operative site following laryngeal resection; tracheoesophageal voice prostheses placed after laryngectomy are coded separately as device implantation procedures |
| 7 | Qualifier | Z | No Qualifier — no additional qualifier applies to this resection; contrast with Qualifier X (Diagnostic) used exclusively when excision (root operation B) is performed solely to obtain tissue for diagnosis rather than for therapeutic removal |
Root Operation — Resection (T) vs. Excision (B) vs. Diagnostic Qualifier (X)
- Use Resection (T) —
0CTS0ZZ— when the entire larynx is removed (total laryngectomy); per PCS guideline B3.8, Resection is selected whenever the entirety of a body part is taken out, and it supersedes Excision even when the operative report uses “subtotal” or “near-total” language if no functional laryngeal tissue remains.- Use Excision (B) with qualifier Z (No Qualifier) —
0CBS0ZZ(open) or0CBS8ZZ(endoscopic) — when only a portion of the larynx is removed with preservation of functional residual tissue, as in supraglottic laryngectomy or transoral laser excision; therapeutic intent is confirmed by qualifier Z.- Use Excision (B) with qualifier X (Diagnostic) —
0CBS8ZX— only when the sole purpose of the endoscopic procedure is tissue sampling for pathological diagnosis; if the procedure removes any tumor for therapeutic intent, qualifier Z applies and0CBS8ZXis incorrect; the operative note must be reviewed to confirm the procedure’s intent before assigning the qualifier.
💊 Coding Scenarios and Examples
Scenario 1 — Surgical Admission: Total Laryngectomy with Bilateral Neck Dissection and Intraoperative Tracheostomy
Clinical Scenario: A 67-year-old male smoker (40 pack-years, current, nicotine dependence documented) with documented alcohol dependence presents for elective total laryngectomy and bilateral modified radical neck dissection for T3N2bM0 SCC of the supraglottic larynx confirmed by direct laryngoscopy and biopsy three weeks prior. The preoperative H&P documents the tumor subsite as the epiglottis and right false vocal cord with pre-epiglottic space extension (T3), and bilateral cervical lymphadenopathy was confirmed by PET-CT and fine-needle aspiration (N2b, bilateral). On postoperative day 3, the attending documents aspiration pneumonia with documented aspiration of oral secretions, confirmed on chest imaging. The attending and dietitian both independently document moderate protein-calorie malnutrition based on preoperative weight loss and serum albumin.
Principal Diagnosis: C32.1 — per ICD-10-CM guideline I.C.2.a, the malignancy is the PDx when the reason for admission is surgical resection of the cancer.
Principal Procedure (ICD-10-PCS): 0CTS0ZZ — Resection, Larynx, Open Approach
| Code | Description | Rationale |
|---|---|---|
| C32.1 | Malignant neoplasm of supraglottis | Principal diagnosis — SCC supraglottis confirmed by pathology and documented by attending; subsite explicitly confirmed as epiglottis and right false vocal cord (both included structures under C32.1) |
| C77.0 | Secondary malignant neoplasm of lymph nodes of head, face, and neck | Additional diagnosis — bilateral cervical N2b disease confirmed by FNA and PET; required per guideline I.C.2.b to capture both primary malignancy and confirmed regional nodal spread |
| J69.0 | Pneumonitis due to inhalation of food and vomit | Additional diagnosis — aspiration pneumonia documented postoperatively by attending; qualifies as a CC; elevates case from DRG 013 to DRG 012 — capture is critical for accurate DRG tier |
| E44.0 | Moderate protein-calorie malnutrition | Additional diagnosis — moderate malnutrition documented by attending and dietitian with clinical support; qualifies as a CC; attending attestation required — dietitian documentation alone is not sufficient |
| F17.210 | Nicotine dependence, cigarettes, uncomplicated | Additional diagnosis — nicotine dependence on cigarettes documented; required by C32 use additional code instruction |
| F10.20 | Alcohol dependence, uncomplicated | Additional diagnosis — alcohol dependence documented by attending; required by C32 use additional code instruction |
DRG Assignment: With
0CTS0ZZas principal procedure and C32.1 as PDx, this case groups to MDC 03, DRG 011/012/013. The confirmed aspiration pneumonia (J69.0, CC) and moderate malnutrition (E44.0, CC) together elevate this to DRG 012 (with CC), assuming no MCC is present. CDI should query for respiratory failure if any clinical indicators exist but are not explicitly documented as a formal diagnosis, as J96.01 would upgrade the case to DRG 011 (MCC), representing the highest reimbursement tier in this DRG family.7,8
Tobacco and Alcohol Codes Are Not Optional
The “use additional code” instruction under C32 is mandatory, not discretionary — F17.210 and F10.20 (or the applicable F10/F17 subcategory) must be assigned whenever tobacco and alcohol diagnoses are documented by the provider, regardless of whether the coder believes they affect reimbursement. Omitting these codes on audit is a documentation compliance finding, and in certain DRG groupings these comorbidities may qualify as CCs that produce tier uplift.1,4
Scenario 2 — Chemotherapy Admission: Induction Cisplatin/5-FU for Unresectable Supraglottic SCC
Clinical Scenario: A 58-year-old male is admitted for induction chemotherapy (cisplatin and 5-fluorouracil) for T4aN3M0 SCC of the supraglottis, deemed unresectable at multidisciplinary tumor board review due to prevertebral fascia involvement and bilateral level II-IV cervical nodal disease. The H&P explicitly documents the supraglottic subsite and documents significant pre-treatment weight loss of 18 lbs over 8 weeks; the attending and registered dietitian both document severe protein-calorie malnutrition based on clinical assessment, anthropometric data, and biochemical markers. The patient has active nicotine dependence and a prior history of radiation therapy to the neck for a different diagnosis (documented as personal history of irradiation). No surgical procedures are performed during the admission — chemotherapy administration is the sole therapeutic purpose.
Principal Diagnosis: Z51.11 — per ICD-10-CM guideline I.C.2.e, when the admission is solely for chemotherapy administration, the therapy encounter code is PDx.
| Code | Description | Rationale |
|---|---|---|
| Z51.11 | Encounter for antineoplastic chemotherapy | Principal diagnosis — admission solely for chemotherapy; per guideline I.C.2.e, Z51.11 is PDx and C32.1 is sequenced as additional diagnosis; reversing this sequence causes incorrect DRG grouping |
| C32.1 | Malignant neoplasm of supraglottis | Additional diagnosis — the active malignancy being treated; explicitly documented subsite (supraglottis) makes C32.1 correct; C32.9 must not be assigned when subsite is documented |
| C77.0 | Secondary malignant neoplasm of lymph nodes of head, face, and neck | Additional diagnosis — N3 bilateral cervical nodal disease confirmed; required per guideline I.C.2.b |
| E43 | Unspecified severe malnutrition | Additional diagnosis — severe malnutrition documented by attending and dietitian with clinical support data; qualifies as an MCC; elevates this case to DRG 847 — attending attestation of “severe” is required and is a high-yield CDI query trigger |
| F17.210 | Nicotine dependence, cigarettes, uncomplicated | Additional diagnosis — active nicotine dependence documented; required by C32 use additional code instruction |
| Z92.3 | Personal history of irradiation | Additional diagnosis — prior radiation to the neck documented; clinically relevant to treatment planning, complication risk, and field design for current radiation planning |
DRG Assignment: With Z51.11 as PDx (no OR procedure), this case groups to MDC 17, DRG 847/848/849. The documented severe malnutrition (E43, MCC) elevates this to DRG 847 (with MCC), the highest reimbursement tier in this DRG family. Capturing E43 rather than E44.0 requires explicit attending documentation of “severe” malnutrition — when clinical indicators support severe malnutrition but the severity level is unstated in the provider documentation, a CDI query is warranted and represents high-yield DRG optimization opportunity.1,7,8
Sequencing Is DRG-Determinative — Z51.11 Must Be PDx
Placing C32.1 as PDx for a pure chemotherapy admission is a sequencing error that causes the case to group to a different MDC and DRG family than intended — a pure chemotherapy admission must group to MDC 17 with Z51.11 as PDx, not to MDC 03 with C32.1 as PDx. This error is among the most commonly cited oncology coding findings in MAC pre-payment review and OIG audits; the financial and compliance exposure of systematic C32.1-as-PDx sequencing for chemotherapy admissions is significant and can trigger targeted review of the entire oncology coding program.1,7,8
Scenario 3 — Surveillance Admission: Biopsy of Suspected Locoregional Recurrence
Clinical Scenario: A 63-year-old female with a documented history of T2N1M0 SCC of the supraglottis treated with definitive concurrent chemoradiation 20 months prior presents for inpatient evaluation of a new supraglottic mass identified on surveillance PET-CT, with FDG-avid uptake at the primary site and right cervical nodes. The admitting diagnosis is “suspected recurrence of supraglottic SCC, pending biopsy.” Flexible laryngoscopy with biopsy is performed under general anesthesia. The pathology report returns squamous cell carcinoma consistent with recurrent primary. The attending otolaryngologist documents the discharge diagnosis as “recurrent malignant neoplasm of the supraglottis.” The patient is currently on no active treatment and has documented nicotine dependence.
Principal Diagnosis: C32.1 — inpatient coding guidelines permit coding the confirmed discharge diagnosis; the attending has confirmed recurrent supraglottic SCC at discharge; the personal history code Z85.21 is not the principal diagnosis here.
Principal Procedure (ICD-10-PCS): 0CBS8ZX — Excision, Larynx, Via Natural or Artificial Opening Endoscopic, Diagnostic
| Code | Description | Rationale |
|---|---|---|
| C32.1 | Malignant neoplasm of supraglottis | Principal diagnosis — recurrent SCC confirmed by pathology and documented by attending at discharge; per ICD-10-CM guidelines, active recurrent malignancy is coded with the primary malignancy code (C32.1), not the personal history code |
| C77.0 | Secondary malignant neoplasm of lymph nodes of head, face, and neck | Additional diagnosis — right cervical nodal involvement confirmed on PET and clinical examination; document per guideline I.C.2.b |
| Z85.21 | Personal history of malignant neoplasm of larynx | Additional diagnosis — appropriate as a secondary code alongside active C32.1 to reflect prior treatment history; must never be used as the sole or principal code when active recurrence is confirmed |
| Z92.3 | Personal history of irradiation | Additional diagnosis — prior radiation to the larynx and neck; clinically relevant to re-treatment planning, complication risk profile, and reirradiation candidacy assessment |
| F17.210 | Nicotine dependence, cigarettes, uncomplicated | Additional diagnosis — active nicotine dependence documented; required per C32 use additional code instruction |
Recurrence vs. History — The Critical Coding Rule for Surveillance Admissions
When a malignancy recurs at the original primary site, ICD-10-CM instructs coders to assign the active malignancy code (C32.1), not the personal history code (Z85.21); Z85.21 applies only when the provider has explicitly documented that treatment is completed and there is no current evidence of active disease. In this scenario, Z85.21 is correctly assigned as an additional code alongside C32.1 to reflect treatment history, but C32.1 is the PDx because active recurrence is confirmed. A critical inpatient coding principle applies: prior to biopsy results, if the admission documentation says only “suspected recurrence,” inpatient guidelines allow waiting for the attending’s confirmed discharge diagnosis — coders must not assign C32.1 based solely on PET-CT findings without attending confirmation, but once the discharge summary confirms recurrent SCC, C32.1 is the correct principal diagnosis for the admission.1,4
⚠️ Coding Pitfalls and Tips
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Defaulting to C32.9 without exhausting the chart for subsite documentation: The most prevalent and consequential coding error for laryngeal malignancy is assigning C32.9 (larynx, unspecified) when operative reports, pathology reports, or progress notes contain explicit subsite language that supports C32.1. Coders must review the full chart — not just the H&P — before concluding that subsite documentation is absent; when documentation is genuinely absent after chart review, a CDI query must be generated, not a silent default to C32.9. Systematically assigning C32.9 suppresses HCC accuracy, creates clinical documentation discrepancies, and undermines tumor registry integrity in a way that will surface in oncology-specific audit programs.1,4
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Assigning C32.1 for all epiglottic tumors without confirming surface location: Coders who see “epiglottic carcinoma” or “epiglottis SCC” in a diagnosis default to C32.1, but when the operative or pathology report specifies the anterior (lingual) surface, the correct code is C10.1 — an oropharyngeal malignancy that belongs to a different anatomical category and carries different MDC, tumor registry, and treatment protocol implications. Any epiglottic cancer report that does not explicitly specify posterior (laryngeal) vs. anterior (lingual) surface should trigger a CDI query before code assignment is finalized; the cost of this query is trivial compared to the downstream audit and registry consequences of systematic mislocation.1,2,3
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Omitting mandatory use additional codes for tobacco and alcohol: The “use additional code” instruction under C32 requires documentation and coding of tobacco and alcohol diagnoses whenever they appear in the medical record — this is a compliance obligation, not an optional enhancement. F17.210-F17.219 (nicotine dependence), Z72.0 (tobacco use), F10.10/F10.20 (alcohol abuse/dependence), and related codes must be captured on every claim where the provider has documented these conditions, and their absence in the presence of documented use is a codable documentation gap that CDI programs should flag during concurrent review of all laryngeal cancer admissions.1,4
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Incorrect PDx sequencing for chemotherapy or radiation-only admissions — the most commonly audited oncology sequencing error: When a patient is admitted solely for antineoplastic chemotherapy (Z51.11) or radiation therapy (Z51.0) in the context of active C32.1, the therapy encounter code must be the PDx and C32.1 is an additional diagnosis per ICD-10-CM guideline I.C.2.e; placing C32.1 as PDx for a pure therapy admission causes the case to group to MDC 03 instead of the correct MDC 17 DRG family, generating a DRG assignment mismatch with direct reimbursement and compliance consequences that accumulate rapidly across an oncology program.1,7,8
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Coding Z85.21 as the sole or principal code for a recurrence admission: Z85.21 (personal history of malignant neoplasm of larynx) applies only after treatment is completed and the provider has documented no evidence of active disease — it is never appropriate as the PDx or sole diagnosis for an admission involving active tumor, recurrence confirmation, or ongoing treatment. Coders who encounter Z85.21 prominently listed on a problem list for a patient presenting with new laryngeal findings must review the discharge summary and pathology results before finalizing the code; if the attending confirms recurrence, C32.1 is the PDx regardless of what is listed on the problem list.1,4
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Missed MCC and CC capture — under-DRG assignment in laryngeal cancer surgical admissions: Laryngeal cancer admissions carry a high burden of clinically expected but frequently underdocumented MCCs and CCs — severe malnutrition (E43, MCC), respiratory failure (J96.01, J96.11, MCC), aspiration pneumonia (J69.0, CC), and moderate malnutrition (E44.0, CC) are all common in this population and directly determine whether a case groups to DRG 011, 012, or 013. The reimbursement differential between DRG 011 (MCC) and DRG 013 (no CC/MCC) can be substantial; CDI programs should build pre-admission and concurrent review triggers for malnutrition assessment, aspiration risk, and respiratory status in every total laryngectomy admission, and query templates should specifically target attending attestation of malnutrition severity when clinical indicators are documented by nursing or dietary staff but the formal diagnosis severity level is unstated in the physician record.4,7,8
📚 Sources
1 ICD-10-CM Official Guidelines for Coding and Reporting, FY2026 (effective October 1, 2025), Centers for Disease Control and Prevention (NCHS) and CMS — Section I.C.2 (Neoplasms), I.C.2.a (Malignancy as principal diagnosis), I.C.2.b (Malignancy with metastatic spread), I.C.2.d (Signs and symptoms associated with neoplasms), I.C.2.e (Therapy encounter as principal diagnosis). 2 National Comprehensive Cancer Network (NCCN) — NCCN Clinical Practice Guidelines in Oncology: Head and Neck Cancers, current version — Laryngeal Cancer section (Supraglottic). 3 AJCC Cancer Staging Manual, 8th Edition — Chapter 16: Larynx (American Joint Committee on Cancer, Springer, 2017); T-staging criteria for supraglottic subsite and lymph node classification. 4 AHIMA/ACDIS — Clinical Documentation Integrity Practice Brief: Oncology and Malignant Neoplasms Coding Guidance (current edition); CDI query triggers for laryngeal subsite specification, malnutrition severity, and tobacco/alcohol documentation. 5 CMS — CMS-HCC Risk Adjustment Model V28: Diagnosis-to-HCC Crosswalk and Hierarchical Condition Categories, published at CMS.gov/Medicare/Health-Plans/MedicareAdvtgSpecRateStats/Risk-Adjustors (2024). ⚠️ Verify C32.1 HCC assignment and RAF weight against the current published V28 crosswalk file. 6 CMS — Announcement of Calendar Year 2024 Medicare Advantage Capitation Rates and Part C and Part D Payment Policies (April 2023); CMS-HCC V28 full implementation and cancer hierarchy restructuring. 7 CMS — FY2025 IPPS Final Rule (CMS-1808-F); MS-DRG Version 42.0 Definitions Manual, MDC 03 (Ear, Nose, Mouth and Throat) Surgical and Medical Partition Logic; DRG 011/012/013 (Tracheostomy for Face, Mouth & Neck Diagnoses or Laryngectomy), DRG 148/149/150 (Major Head and Neck Procedures). ⚠️ Verify DRG relative weights against the current IPPS Final Rule for the applicable fiscal year. 8 CMS — MS-DRG Grouper Version 42.0 Logic: DRG 847/848/849 (Chemotherapy), MDC 17; PDx sequencing rules for antineoplastic therapy encounters (Z51.11, Z51.0) per ICD-10-CM guideline I.C.2.e. 9 CMS — National Correct Coding Initiative (NCCI) Policy Manual for Medicare Services, Chapter 4 (Head and Neck Procedures), current edition — bundling rules applicable to laryngoscopy, laryngectomy, and neck dissection code pairs (CPT 31360, 31365, 31367, 31368, 31541, 31576).