31571

🎙️ CPT 31571 — Laryngoscopy, Direct, With Injection Into Vocal Cord(s), Therapeutic; With Operating Microscope Or Telescope

Quick Reference

wRVU: 4.15¹ | Global Period: 000 | Assistant Payable: No (minor endoscopic procedure, no separately payable assistant-at-surgery under standard MPFS indicators) | Bilateral Indicator: 2 Rule: CPT 31571 carries a 000-day global because it’s an endoscopic injection procedure, not open surgery, so postoperative E/M visits within the global window are separately billable when unrelated to the injection. The bilateral indicator of 2 reflects the “vocal cord(s)” descriptor — CMS does not apply the usual 150% bilateral payment adjustment because the code already contemplates injection of one or both cords in a single session.

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📋 Clinical Description

CPT 31571 describes a direct (rigid) laryngoscopy performed under general or local anesthesia in which the surgeon suspends a rigid laryngoscope to visualize the glottis, then uses an operating microscope or telescope for magnification while injecting a therapeutic or bulking substance into the body of one or both vocal cords. The injected material — often a temporary agent like carboxymethylcellulose gel or a longer-acting option like calcium hydroxylapatite — is placed in the paraglottic space lateral to the thyroarytenoid muscle to bulk up a paralyzed, atrophic, or bowed cord and push it toward the midline, improving glottic closure during phonation. This differs from 31570, its direct-visualization sibling performed without a microscope or telescope, and from 31574, which achieves the same medialization goal but via a flexible transoral or percutaneous approach without suspension laryngoscopy.

The choice between these sibling codes hinges entirely on instrumentation and approach, not on intent — all three treat the same underlying pathology (typically unilateral vocal cord paralysis) but differ in how the surgeon accesses and visualizes the cord. 31571’s use of an operating microscope gives superior magnification for precise needle placement compared to 31570, which is billed when the surgeon injects under direct laryngoscopic view alone. Because the procedure is performed with a suspension laryngoscope in the OR, it is distinct from office-based awake procedures reported with 31573 or 31574, which use flexible endoscopy and local anesthesia instead.

This procedure may be performed in the following clinical contexts:

• Unilateral vocal cord paralysis — Most commonly performed after recurrent laryngeal nerve injury from thyroid, parathyroid, cardiothoracic, or skull base surgery, to restore glottic closure and reduce aspiration risk and breathy dysphonia.
• Presbylarynx / vocal cord atrophy — Age-related bowing of the cords can be treated with augmentation injection to improve voice projection and reduce vocal fatigue.
• Vocal cord scarring or sulcus vocalis — Injection of a bulking or hydrating agent can improve mucosal wave and voice quality in scarred cords.
• Trial (“test”) injection prior to permanent laryngoplasty — A temporary agent is injected to confirm that medialization will improve voice before committing to a permanent surgical procedure like thyroplasty.

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🔬 Anatomical & Procedural Considerations

Variant	Mechanism	Key Notes
Temporary Injection (e.g., carboxymethylcellulose gel)	The surgeon injects a resorbable gel into the paraglottic space using a laryngeal injection needle passed through the suspended laryngoscope under microscopic visualization. The gel provides bulk for weeks to a few months as it is gradually resorbed.	Frequently used as a diagnostic trial before a patient commits to permanent surgical medialization (thyroplasty or arytenoid adduction); also appropriate for paralysis expected to recover spontaneously.
Long-Acting/Permanent Injection (e.g., calcium hydroxylapatite)	A denser, longer-lasting material is placed in the same paraglottic plane; the surgeon typically injects incrementally while assessing cord position and voice response intraoperatively.	Chosen when nerve recovery is unlikely (e.g., nerve transection) or when the patient has failed temporary injections and wants a more durable result without open thyroplasty.
Bilateral Injection	Both cords are injected sequentially in the same session, still reported as a single unit under CPT 31571 since the descriptor covers “vocal cord(s).”	Less common — typically reserved for bilateral bowing/atrophy rather than bilateral paralysis, since bilateral paralysis usually presents with airway obstruction rather than a medialization problem.

Clinical Pearl

Because the code descriptor already says “vocal cord(s),” do not append modifier -50 even if both cords are injected in the same operative session — report 31571 once regardless of how many cords were treated. Watch operative notes carefully for “flexible” versus “rigid/direct” laryngoscopy language, since that single word determines whether 31571 or 31574 is the correct code, and payers frequently deny claims where the documentation and code selection don’t match on scope type.

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✅ Procedure Includes

• Suspension of the rigid laryngoscope and initial diagnostic assessment of vocal cord mobility and glottic closure.
• Use of the operating microscope or telescope for magnified visualization throughout the injection.
• Preparation and loading of the injectable material (though the material itself, e.g., HCPCS L8607 or Q-codes, is separately billable).
• Injection of the therapeutic/bulking agent into one or both vocal cords.
• Intraoperative assessment of vocal cord position and glottic closure after injection.
• Removal of the laryngoscope and immediate post-procedure airway check.

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❌ Excludes / Do Not Report Together

Code	Description	Relationship
31570	Laryngoscopy, direct, with injection into vocal cord(s), therapeutic	Mutually exclusive with 31571 — the two codes differ only by whether an operating microscope or telescope was used, so only one should ever be reported for the same encounter; report whichever matches the documented equipment.
31573	Laryngoscopy, flexible; with therapeutic injection(s) (e.g., chemodenervation agent, corticosteroid, other pharmacologic agent)	Distinguished by scope type (flexible vs. direct/rigid) and by injected substance category; if the documentation describes a flexible transnasal scope rather than a suspended rigid laryngoscope, 31573 is correct instead of 31571.
31574	Laryngoscopy, flexible; with injection(s) for augmentation (e.g., percutaneous, transoral), unilateral	Represents the awake, office-based, flexible-scope equivalent of the same clinical goal (vocal cord augmentation); should not be billed alongside 31571 for the same session since they describe different approaches to the same treatment.
31599	Unlisted procedure, larynx	Only appropriate when the operative report describes a laryngeal procedure with no matching specific CPT code — should never be used simply because 31571’s documentation requirements weren’t fully met; query the physician instead.

Bundling Alert

CPT 31571 carries a 000-day global period, so any related E/M service performed on the same date is bundled into the procedure and generally should not be billed separately without modifier -25 supporting a significant, separately identifiable service. Because 31570 and 31571 differ only by equipment used, auditors frequently flag claims where operative notes fail to explicitly document use of the microscope or telescope — absent that documentation, payers may downcode to 31570, so make sure the equipment is clearly stated before finalizing the higher-valued code.

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🌳 Code Tree — Surgery: Larynx (Endoscopy)

CPT 31505-31579  Surgery: Respiratory System, Larynx, Endoscopy
│
├── 31505-31513  Laryngoscopy, Indirect
│   ├── 31505  Laryngoscopy, indirect; diagnostic
│   └── 31513  Laryngoscopy, indirect; with vocal cord injection
│
├── 31515-31530  Laryngoscopy, Direct, Diagnostic
│   ├── 31515  Laryngoscopy, direct, with or without tracheoscopy; for aspiration
│   └── 31527  Laryngoscopy, direct, operative, with injection into vocal cord(s) for augmentation (deleted/bundled historically — verify current status before use)
│
├── 31560-31571  Laryngoscopy, Direct, Operative — Injection & Vocal Cord Procedures
│   ├── 31560  Laryngoscopy, direct, with arytenoidectomy; with operating microscope or telescope
│   ├── ▶▶ 31570 ◀◀  Laryngoscopy, direct, with injection into vocal cord(s), therapeutic
│   ├── ▶▶ 31571 ◀◀  Laryngoscopy, direct, with injection into vocal cord(s), therapeutic; with operating microscope or telescope  ← YOU ARE HERE  (Global: 000)
│   └── 31576  Laryngoscopy, direct, with injection of botulinum toxin into laryngeal muscles(s), unilateral
│
├── 31572-31578  Laryngoscopy, Direct, Operative — Excision/Removal
│   ├── 31572  Laryngoscopy, direct, with injection into vocal cord(s) for augmentation, unilateral (flexible/direct combination code family)
│   └── 31578  Laryngoscopy, direct, with removal of foreign body
│
└── 31579-31599  Laryngoscopy, Flexible & Unlisted
    ├── 31579  Laryngoscopy, flexible or rigid telescopic, with stroboscopy
    └── 31599  Unlisted procedure, larynx

Note: The immediate neighbors of 31571 in the CPT larynx endoscopy family have shifted across recent code cycles (several augmentation/injection codes were revised when 31573/31574 were created); confirm exact adjacent code numbers and descriptors against your current AAPC/AMA codebook before finalizing documentation.

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💰 RVU & Reimbursement Profile

Component	Value
Work RVU	4.15¹
Global Period	000 — no pre- or post-operative period bundled beyond the day of service
Bilateral Indicator	2 — the usual 150% bilateral payment adjustment does not apply because the code descriptor (“vocal cord(s)”) already contemplates injecting either or both cords
Assistant Surgeon	Not typically separately payable — this is a single-surgeon endoscopic procedure under standard MPFS indicators
Co‑Surgeon	Not applicable — no defined anatomic split requiring two primary surgeons
Team Surgery	Not applicable
PC/TC Split	0 — global service; the code does not split into separate professional and technical components
Modifier -51 Exempt	No — standard multiple-procedure reduction rules apply when billed with other same-session procedures
Anesthesia	Typically performed under general anesthesia in the OR; anesthesia is separately billable by the anesthesia provider under the corresponding CPT anesthesia code for laryngeal procedures

Bilateral Billing Rules

Because bilateral indicator 2 applies, report 31571 as a single unit regardless of whether one or both cords were injected — do not append modifier -50, and do not bill two units with -RT/-LT. If the operative note distinguishes right versus left findings for clinical clarity, that belongs in the documentation narrative, not in separate line items.

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🏷️ Modifier Reference

Modifier	Name	When to Apply
-RT	Right Side	Informational only when only the right vocal cord was injected; does not change payment since the code is not unit-based by side.
-LT	Left Side	Informational only when only the left vocal cord was injected; same non-payment-impacting use as -RT.
-50	Bilateral	Generally not appended to 31571 given bilateral indicator 2 — confirm with your MAC/payer before using, as this is a frequent point of denial.
-25	Significant E/M	Append to a same-day E/M code when a significant, separately identifiable evaluation was performed in addition to the injection procedure, such as a new-problem workup unrelated to the vocal cord issue.
-51	Multiple Procedures	Apply when 31571 is billed with another separately reportable surgical procedure in the same session, subject to standard multiple-procedure payment reduction.
-59	Distinct Service	Use when 31571 must be distinguished from a bundled code that would otherwise be denied as part of the same session, such as a separate, unrelated laryngeal procedure performed through the same scope insertion.
-22	Increased Procedural Services	Supports additional payment when the operative note documents substantially increased complexity or time, such as difficult exposure from prior neck surgery or radiation changes.
-52	Reduced Services	Applied when the injection was attempted but not fully completed as planned, such as inability to achieve adequate cord exposure.
-78	Return to OR	Applies when the patient is returned to the OR during the global period for a related procedure, such as a repeat injection after an inadequate first result — since global is 000 days, this scenario is rare but can occur with same-day staged approaches.

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🩺 Common ICD‑10‑CM Pairings

Primary Diagnosis Group

ICD‑10	Description	HCC?	Notes
J38.00	Paralysis of vocal cords and larynx, unspecified	❌ No	Use only when laterality isn’t documented; query the physician for unilateral vs. bilateral whenever possible since it changes both clinical management and code specificity.
J38.01	Paralysis of vocal cords and larynx, unilateral	❌ No	The most common indication for 31571 — typically follows recurrent laryngeal nerve injury from thyroid, cardiothoracic, or skull base surgery.
J38.02	Paralysis of vocal cords and larynx, bilateral	❌ No	Bilateral paralysis more often presents with airway compromise; confirm the note supports an augmentation goal rather than an airway procedure before pairing with 31571.
R49.0	Dysphonia	❌ No	Appropriate secondary or standalone symptom code when the underlying cause of the voice change hasn’t been established at the time of injection.
J38.1	Polyp of vocal cord and larynx	❌ No	Not the typical indication for augmentation injection but may coexist with paralysis in complex laryngeal presentations.

Secondary Group

ICD‑10	Description	HCC?	Notes
R49.1	Aphonia	❌ No	Supports medical necessity when the patient has complete voice loss rather than partial breathiness.
C32.0	Malignant neoplasm of glottis	✅ Yes	Use when vocal cord paralysis or augmentation need stems from laryngeal malignancy or its treatment; this is an HCC-relevant code so ensure it’s supported by current active disease documentation, not history alone.

Etiology / Complication

ICD‑10	Description	HCC?	Notes
G52.2	Disorders of vagus nerve	❌ No	Appropriate when the operative note attributes the paralysis to vagal or recurrent laryngeal nerve injury, such as intraoperative nerve trauma.
Z98.890	Other specified postprocedural states	❌ No	Useful secondary code when the vocal cord paralysis is a known sequela of a prior surgery, such as thyroidectomy, and the documentation explicitly ties the two together.

Coding Specificity Reminder

Always query for laterality (unilateral vs. bilateral) and, where documented, the underlying etiology (iatrogenic nerve injury, idiopathic, malignancy-related, or age-related atrophy) before finalizing the diagnosis. J38.00 should be a last resort — most operative and clinic notes for this procedure will support a more specific unilateral or bilateral code.

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🏥 MS‑DRG Considerations

When 31571 is the principal or a significant secondary OR procedure on an inpatient claim, it groups within MDC 3 (Ear, Nose, Mouth & Throat), typically to MS-DRGs 146 or 147 (Ear, Nose, Mouth, and Throat O.R. Procedures with or without MCC) depending on secondary diagnosis complexity and comorbidities. If performed alongside a more extensive head and neck procedure (e.g., concurrent neck dissection or laryngectomy), the case may instead group to the Major Head & Neck Procedures DRGs (129–130), so review the full operative day’s procedure list before finalizing the DRG assignment. No National Coverage Determination (NCD) specifically addresses vocal cord injection; coverage is governed by general Medicare reasonable-and-necessary standards, and no active Noridian JE/JF Local Coverage Determination (LCD) was identified that specifically restricts 31570/31571 — confirm current status in the Medicare Coverage Database before assuming automatic coverage, since some non-Medicare payers (including certain commercial and Medicaid MCO policies) apply their own medical policy criteria for bulking-agent injections that go beyond CMS’s general standard.²

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🔧 ICD‑10‑PCS Equivalents

PCS Code	Full Description	Modality
0C1P8ZZ	Insertion of Substitute into Larynx, Via Natural or Artificial Opening Endoscopic	Endoscopic injection/insertion approach
0C1PXZZ	Insertion of Substitute into Larynx, External Approach	External approach, used if injection performed via external access rather than endoscopically
0CQP8ZZ	Repair Larynx, Via Natural or Artificial Opening Endoscopic	May apply if the procedure is characterized as a structural repair rather than substance insertion
0CQPXZZ	Repair Larynx, External Approach	External-approach equivalent of the repair root operation

PCS Character Analysis

Position	Character	Value	Definition
1	Section	0	Medical and Surgical section — covers the vast majority of OR procedures, including laryngeal injections performed for therapeutic augmentation.
2	Body System	C	Mouth and Throat body system, which includes the larynx and vocal cords as approved PCS body parts.
3	Root Operation	1 (Insertion)	Reflects placement of a non-biological therapeutic substance (the bulking agent) into the vocal cord without taking over a body part’s function — Insertion is used because the material stays without displacing structure.
4	Body Part	P (Larynx)	PCS does not further subdivide “vocal cord” from “larynx” as distinct body parts, so Larynx is used regardless of which specific cord was injected.
5	Approach	8 (Via Natural or Artificial Opening Endoscopic)	Reflects that the injection was delivered endoscopically through a suspended laryngoscope rather than through an external incision.
6	Device	Z (No Device)	No device remains implanted; injectable substances are coded via the root operation itself, not as a device.
7	Qualifier	Z (No Qualifier)	No additional qualifier applies to this body part/approach/root-operation combination.

Root Operation Comparison

• Insertion (0C1P8ZZ) is correct when a bulking or augmentation substance is placed without altering the cord’s underlying anatomy — this is the standard root operation for CPT 31571.
• Repair (0CQP8ZZ) would only apply if the procedure were characterized as restoring anatomic structure or function beyond simple substance placement, which is not typical for a straightforward augmentation injection.
• Always confirm root operation selection against the specific wording of the operative note rather than defaulting from the CPT code alone, since PCS root operation logic is procedure-based, not CPT-crosswalk-based.

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📝 Coding Examples

Example 1

Clinical Scenario: A 62-year-old male with left recurrent laryngeal nerve paralysis following thyroidectomy 3 months ago presents for vocal cord augmentation. Under general anesthesia, the surgeon suspends a rigid laryngoscope and, using the operating microscope, injects carboxymethylcellulose gel into the left vocal cord to medialize it and improve glottic closure.

Field	Code	Rationale
CPT	31571--LT	Direct laryngoscopy with therapeutic injection using the operating microscope; -LT is informational only since bilateral indicator 2 means no payment impact.
PDx	J38.01	Documented unilateral (left) vocal cord paralysis is the indication for the injection.

Note

Confirm the operative note explicitly states “operating microscope” or “telescope” — absent that language, this claim should default to 31570 instead.

Example 2

Clinical Scenario: A 55-year-old female with bilateral vocal cord bowing from presbylarynx undergoes staged direct laryngoscopy with microscope-guided injection of calcium hydroxylapatite into both cords in the same operative session, along with a separately documented diagnostic microlaryngoscopy for an unrelated area of leukoplakia.

Field	Code	Rationale
CPT 1	31571	Single unit reported for injection into both cords per bilateral indicator 2 — no modifier -50 or duplicate units.
CPT 2	31535--59	Separate diagnostic biopsy of an unrelated laryngeal lesion, distinct from the injection procedure, supports modifier -59 if both are separately documented and medically necessary.
PDx	J38.02	Bilateral vocal cord bowing/atrophy is the primary indication for augmentation.

Warning

Do not bill 31571 twice or append -50 for bilateral cord injection — this is a frequent overbilling error that will trigger payer audit and recoupment.

Example 3

Clinical Scenario: A 70-year-old male with unilateral vocal cord paralysis of unknown duration returns to the OR one week after an initial temporary gel injection because the effect has already resorbed and the patient wants a longer-acting agent. The same direct laryngoscopy with microscope-guided injection technique is repeated.

Field	Code	Rationale
CPT	31571	Repeat injection procedure using the same approach and equipment as the original.
PDx	J38.01	Unchanged underlying diagnosis of unilateral vocal cord paralysis.

Global period reminder, if applicable

Because 31571 carries a 000-day global period, this repeat procedure is separately billable without a global-period modifier, even though it occurred only one week after the first injection.

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⚠️ Common Coding Pitfalls

• Pitfall 1: Confusing 31570 and 31571 based on assumption rather than documentation — always confirm the operative note explicitly states use of an operating microscope or telescope before selecting 31571; absent that language, default to 31570.
• Pitfall 2: Appending modifier -50 or billing two units for bilateral cord injection — the code’s bilateral indicator of 2 means the base value already accounts for injecting one or both cords in a single session.
• Pitfall 3: Selecting 31571 when the operative note actually describes a flexible transnasal or transoral scope rather than a suspended rigid laryngoscope — that scenario belongs to 31573 or 31574 instead.
• Pitfall 4: Defaulting to unspecified laterality (J38.00) without querying the physician — most operative documentation supports a more specific unilateral or bilateral paralysis code, which better reflects clinical severity and supports medical necessity.
• Pitfall 5: Failing to separately capture the injectable material (e.g., HCPCS L8607 or the applicable Q-code) — the CPT code represents the procedure only; the substance itself is a separately reportable supply when billed by the facility.
• Pitfall 6: Overlooking the 000-day global period and unnecessarily appending modifier -79 or -58 for a same-week repeat injection — since there is no global period bundling to override, those modifiers aren’t needed for a straightforward repeat procedure.

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📎 Sources

1. RVU Edge. *CPT 31571 — Laryngoscopy with VC Injection + Scope wRVU Reference.* National estimate based on 2026 CMS PFS Conversion Factor ($33.40); accessed 2026. https://rvuedge.com/cpt-codes/surgery/31571/ 2. American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS). *CPT for ENT: Chemodenervation of the Larynx and Flexible Laryngoscopic Procedures.* AAO-HNS Coding Resources; 2023–2025. https://www.entnet.org 3. Centers for Medicare & Medicaid Services. *CY 2026 Medicare Physician Fee Schedule Final Rule (CMS-1832-F).* CMS.gov; 2025.

_{Sources listed above correspond to superscript citations throughout this note. Verify all Medicare payment figures against your current CMS PFS Lookup tool and applicable MAC LCD prior to claim submission. Please use the latest AAPC/AHIMA Coding Books to verify each code within this note.}