🎤 CPT 31570 — Laryngoscopy, Direct, With Injection Into Vocal Cord(s), Therapeutic
Quick Reference
wRVU: 3.76 | Global Period: 000 | Assistant Payable: No | Bilateral Indicator: 2 Rule: CPT 31570 carries a 000-day global (minor endoscopic procedure — no pre-op period, same-day post-op only). Its bilateral indicator of 2 means the “(s)” in the descriptor already covers unilateral or bilateral injection in a single code — modifier -50 does not apply and does not increase payment.¹
📋 Clinical Description
CPT 31570 describes a transoral direct laryngoscopy during which the physician passes a rigid laryngoscope to visualize the larynx and injects a therapeutic agent — most commonly corticosteroid, botulinum toxin, or a bulking/augmentation material — directly into one or both vocal cords.² This combines diagnostic visualization with a therapeutic injection in a single encounter, most often performed under general anesthesia or moderate sedation in an OR or procedure suite setting.
The sibling code 31571 describes the identical injection technique but adds an operating microscope or telescope for magnified visualization, typically chosen when finer injection precision is clinically indicated.³ Compare also to 31513 (indirect laryngoscopy with vocal cord injection, an older/awake technique) and 31574 (flexible laryngoscopy with injection, the modern “awake” percutaneous or transoral approach) — coding trend data shows utilization has been shifting from operative codes like 31570/31571 toward awake injection codes over the past two decades as office-based laryngology techniques have matured.⁴
This procedure may be performed in the following clinical contexts:
- Unilateralvocal cord paralysis — injection augmentation (temporary filler) to medialize a paralyzed cord and improve glottic closure, voice quality, and swallow safety.
- Spasmodic dysphonia — botulinum toxin chemodenervation injected directly into the thyroarytenoid muscle via direct laryngoscopy to reduce involuntary laryngeal spasm.
- Vocal fold scar or sulcus — corticosteroid injection to reduce fibrosis and improve vocal fold pliability.
- Bilateral vocal cord paralysis with airway compromise — staged injection augmentation as part of a broader airway management plan, often performed in conjunction with other laryngeal procedures.
🔬 Anatomical & Procedural Considerations
| Variant | Mechanism | Key Notes |
|---|---|---|
| 31570 — Direct laryngoscopy, unaided | Rigid laryngoscope suspended for direct line-of-sight visualization; injection performed freehand or with a laryngeal injector under direct vision without magnification. | Chosen when the vocal cord anatomy is straightforward to visualize and magnification isn’t clinically necessary; typically the faster of the two operative approaches. |
| 31571 — Direct laryngoscopy with microscope/telescope | Same suspension technique, but magnified visualization via an operating microscope or rigid telescope allows more precise needle placement. | Preferred for smaller or more technically demanding injections, such as fine augmentation for thin or atrophic cords. |
| 31574 — Flexible (awake) laryngoscopy with injection | Flexible fiberoptic scope passed transnasally in an awake patient; injection delivered transorally or percutaneously under endoscopic guidance. | Increasingly favored for its avoidance of general anesthesia — a major driver of the utilization shift away from 31570/31571.⁴ |
Clinical Pearl
Documentation must clearly state the injection was performed “via direct laryngoscopy” — if the operative note describes a percutaneous (through-the-neck) approach instead, 31570/31571 are the wrong codes entirely; that scenario reports to the unlisted code 31599 with supporting documentation, not a direct laryngoscopy code.⁵ This is one of the most frequently misapplied code pairs in laryngology billing.
✅ Procedure Includes
- Transoral passage and suspension of the direct laryngoscope for visualization of the larynx and vocal cords.
- Direct visual inspection of the laryngeal structures during scope placement.
- Injection of the therapeutic agent into one or both vocal cords using a laryngeal injector.
- Immediate post-injection observation of the injection site for placement and effect.
- Routine local anesthesia application to the oropharynx/larynx as part of scope tolerance.
- Basic recovery monitoring immediately following the procedure.
❌ Excludes / Do Not Report Together
| Code | Description | Relationship |
|---|---|---|
| 31571 | Laryngoscopy, direct, with injection into vocal cord(s), therapeutic; with operating microscope or telescope | Mutually exclusive — choose one or the other based on whether magnification was used; never report both for the same injection encounter. |
| 31574 | Laryngoscopy, flexible; with injection(s) for augmentation, unilateral | Represents the awake/flexible approach; do not report alongside 31570 for the same injection session — the technique determines which single code applies. |
| 31513 | Laryngoscopy, indirect; with vocal cord injection | Older indirect-mirror technique; distinct code family from direct laryngoscopy and not reported together. |
| 31599 | Unlisted procedure, larynx | Used instead of 31570 when the injection is percutaneous rather than via direct laryngoscopy — not an “and,” an “instead of.” |
Bundling Alert
Because 31570 carries a 000-day global period, any E/M service performed the same day is bundled into the procedure payment unless it represents a significant, separately identifiable service — in which case modifier -25 applies to the E/M code, not to 31570 itself. Watch for NCCI edits when 31570 is billed alongside other same-session laryngeal procedures (e.g., biopsy, excision); many code pairs in the 31500–31599 range have bundling edits that may require modifier -59 or an X{EPSU} modifier with clear operative note support to unbundle appropriately. Audit risk rises sharply when 31570 and 31571 both appear in a provider’s billing pattern without clear microscope/telescope documentation distinguishing them.
🌳 Code Tree — Surgery: Respiratory System, Larynx
31505-31579 Surgical Procedures on the Larynx — Endoscopy Procedures
│
├── 31505-31513 Laryngoscopy, Indirect
│ ├── 31505 Laryngoscopy, indirect; diagnostic
│ └── 31513 Laryngoscopy, indirect; with vocal cord injection
│
├── 31520-31579 Laryngoscopy, Direct
│ ├── 31520 Laryngoscopy, direct, newborn, diagnostic
│ ├── 31535 Laryngoscopy, direct, operative, with biopsy (Global: 010)
│ ├── ▶▶ 31570 ◀◀ Laryngoscopy, direct, with injection into vocal cord(s), therapeutic ← YOU ARE HERE (Global: 000)
│ ├── 31571 Laryngoscopy, direct, with injection into vocal cord(s), therapeutic; with operating microscope or telescope (Global: 000)
│ └── 31579 Laryngoscopy, direct, with stroboscopy (Global: 000)
│
├── 31572-31574 Laryngoscopy, Flexible
│ ├── 31573 Laryngoscopy, flexible; with therapeutic injection(s)
│ └── 31574 Laryngoscopy, flexible; with injection(s) for augmentation, unilateral
│
└── 31599 Unlisted procedure, larynx💰 RVU & Reimbursement Profile
| Component | Value |
|---|---|
| Work RVU | 3.76 (CMS RVU26A, National Unadjusted, CY2026)¹ |
| Global Period | 000 — minor endoscopic procedure; no pre-op period, same-day post-op only |
| Bilateral Indicator | 2 — descriptor already covers unilateral or bilateral injection; modifier -50 not applicable, no payment increase for bilateral injection |
| Assistant Surgeon | Not typically separately payable — single-provider endoscopic procedure |
| Co‑Surgeon | Concept does not apply |
| Team Surgery | Concept does not apply |
| PC/TC Split | 0 — Physician service code; no professional/technical component split applies |
| Modifier -51 Exempt | No — subject to multiple procedure reduction when billed with other same-session surgical codes |
| Anesthesia | Typically general anesthesia or moderate sedation; not separately billed by the performing otolaryngologist |
Bilateral Billing Rules
Because the CPT descriptor already reads “vocal cord(s),” CMS assigns this a bilateral indicator of 2 — the code is paid at the same rate whether one or both cords are injected in the same session. Do not append modifier -50, and do not bill the code twice for a bilateral injection; one line, one unit, regardless of how many cords were treated.
🏷️ Modifier Reference
Only modifiers compatible with 31570 are listed. -RT, -LT, and -50 are excluded — the “(s)” descriptor makes laterality modifiers non-billable/non-payable for this code, since CMS already prices it as covering unilateral or bilateral injection.
| Modifier | Name | When to Apply |
|---|---|---|
| -25 | Significant, Separately Identifiable E/M | Applies to a same-day E/M code (not to [31570]) when a significant, separately documented evaluation is performed beyond the routine pre-procedure assessment. |
| -51 | Multiple Procedures | Applies when 31570 is billed with other separately payable surgical procedures in the same session, subject to standard multiple-procedure payment reduction. |
| -59 | Distinct Procedural Service | Applies when 31570 is performed as a distinct service from another same-day procedure that would otherwise be bundled under NCCI edits, with clear documentation supporting separate sites or sessions. |
| -52 | Reduced Services | Applies if the injection was performed at reduced scope — for example, only a partial dose delivered due to patient tolerance — at physician discretion. |
| -53 | Discontinued Procedure | Applies if the procedure was started but terminated before completion due to patient risk, such as inability to tolerate scope placement. |
| -58 | Staged or Related Procedure | Applies when 31570 is a planned, staged repeat injection performed by the same physician during the postoperative period of a prior related procedure. |
| -78 | Unplanned Return to OR | Applies if an unplanned return to the OR for a related complication occurs during the global period of a prior procedure. |
| -79 | Unrelated Procedure During Postop Period | Applies when 31570 is performed during the global period of an unrelated prior procedure by the same physician. |
NCCI Bundling Considerations
Same-session laryngeal procedures (biopsy, excision, stroboscopy) may carry NCCI Procedure-to-Procedure edits against 31570; verify current edit pairs before appending -59/-51, and ensure the operative note explicitly supports any code combination billed together, since 31570/31571 audits frequently focus on inappropriate unbundling with other endoscopic larynx codes.
🩺 Common ICD‑10‑CM Pairings
Primary Diagnosis Group
| ICD‑10 | Description | HCC? | Notes |
|---|---|---|---|
| J38.01 | Paralysis of vocal cords and larynx, unilateral | ❌ No | Most common indication for injection augmentation; specify laterality whenever documented — avoid defaulting to unspecified. |
| J38.02 | Paralysis of vocal cords and larynx, bilateral | ❌ No | Higher clinical severity due to airway compromise risk; often paired with a broader airway management plan. |
| J38.00 | Paralysis of vocal cords and larynx, unspecified | ❌ No | Use only when laterality is genuinely not documented — query the provider before defaulting here. |
| J38.3 | Other diseases of vocal cords | ❌ No | Captures vocal fold scar, sulcus, granuloma, and spasmodic dysphonia when not separately classified. |
| R49.0 | Dysphonia | ❌ No | Appropriate as a symptom code only when a definitive vocal cord diagnosis has not yet been established. |
Secondary Group
| ICD‑10 | Description | HCC? | Notes |
|---|---|---|---|
| C32.0 | Malignant neoplasm of glottis | ✅ Yes | Supports injection performed for post-oncologic vocal cord dysfunction or augmentation following partial resection. |
| D14.1 | Benign neoplasm of larynx | ❌ No | Relevant when injection follows benign lesion management rather than malignancy. |
Etiology / Complication
| ICD‑10 | Description | HCC? | Notes |
|---|---|---|---|
| C34.90 | Malignant neoplasm of unspecified part of unspecified bronchus or lung | ✅ Yes | Common etiology for recurrent laryngeal nerve palsy causing vocal cord paralysis via tumor compression or post-thoracotomy injury. |
| G70.00 | Myasthenia gravis without (acute) exacerbation | ❌ No | Neuromuscular etiology occasionally underlying vocal cord dysfunction requiring injection management. |
Coding Specificity Reminder
Always code to the highest specificity for laterality on J38.01/J38.02 — unspecified J38.00 should be a query trigger, not a default. When the injection targets a malignancy-related paralysis, sequence the malignancy code first if it is the reason for the encounter, with the vocal cord paralysis as a secondary/manifestation code per ICD-10-CM sequencing conventions.
🏥 MS‑DRG Considerations
On the professional/physician side, CPT 31570 does not itself determine MS-DRG assignment — DRGs are a facility-side concept driven by ICD-10-PCS procedure coding and principal diagnosis. On the facility claim, the corresponding PCS root operation (Introduction of a therapeutic substance) contributes to procedure-driven DRG logic only when it meets OR-procedure criteria; otherwise it functions as a non-OR ancillary procedure that doesn’t independently shift the DRG. There is no dedicated National Coverage Determination (NCD) specific to CPT 31570 itself. Coverage is governed at the Local Coverage Determination (LCD) level tied to the injected substance and indication — most notably, Noridian’s active Botulinum Toxin Injections LCD (L33274) lists both 31570 and 31571 as applicable procedure codes when botulinum toxin is the injected agent for indications such as spasmodic dysphonia, requiring documented medical necessity and, in many jurisdictions, prior authorization for the botulinum toxin HCPCS drug code itself (J0585/J0586/J0587/J0588).⁶
When the injected agent is a corticosteroid or augmentation material rather than botulinum toxin, coverage typically falls under general medical necessity documentation rather than a dedicated LCD — verify the specific injected substance against your MAC’s current coverage database before submission.
🔧 ICD‑10‑PCS Equivalents
| PCS Code | Full Description | Modality |
|---|---|---|
| 3E0F7GC | Introduction of Other Therapeutic Substance into Respiratory Tract, Via Natural or Artificial Opening | Direct laryngoscopic injection, non-endoscopic visualization |
| 3E0F8GC | Introduction of Other Therapeutic Substance into Respiratory Tract, Via Natural or Artificial Opening Endoscopic | Used when the operative note supports endoscopic (camera/scope-assisted) visualization during injection |
| 3E0F7TZ | Introduction of Destructive Agent into Respiratory Tract, Via Natural or Artificial Opening | Applicable when the injected agent is a chemodenervation/destructive agent such as botulinum toxin |
| 3E0F7SF | Introduction of Anti-inflammatory into Respiratory Tract, Via Natural or Artificial Opening | Applicable when the injected agent is a corticosteroid for anti-inflammatory purposes |
PCS Character Analysis
| Position | Character | Value | Definition |
|---|---|---|---|
| 1 | Section | 3 | Administration section — covers putting in or on a therapeutic, diagnostic, nutritional, or prophylactic substance. |
| 2 | Body System | E | Physiological Systems and Anatomical Regions — used for substance administration rather than an organ-specific body system. |
| 3 | Root Operation | 0 | Introduction — placing a therapeutic substance into or onto a body part; matches the injection performed here. |
| 4 | Body Part | F | Respiratory Tract — the closest standard Administration-section body part value covering the larynx/vocal cords. |
| 5 | Approach | 7 or 8 | Via Natural or Artificial Opening (7) for non-scoped direct visualization, or Via Natural or Artificial Opening Endoscopic (8) if camera/scope guidance is documented. |
| 6 | Substance | G, T, or S | Varies by agent: G = Other Therapeutic Substance (augmentation filler), T = Destructive Agent (botulinum toxin), S = Anti-inflammatory (corticosteroid). |
| 7 | Qualifier | Z | No qualifier — most Administration-section codes for this scenario carry no additional qualifier value. |
Root Operation Comparison
- Introduction (root operation 0) is used here because a substance is being placed into the vocal cords without taking a sample or destroying/altering tissue as the primary intent — even though botulinum toxin technically has a destructive mechanism at the neuromuscular junction, PCS coding conventions still classify chemodenervation injections under Introduction with a Destructive Agent substance value, not under the Destruction root operation.
- Always confirm the specific injected agent before finalizing the substance character (position 6) — this single character changes based on corticosteroid vs. botulinum toxin vs. augmentation filler, and picking the wrong one misrepresents the clinical intent of the procedure on the facility claim.
📝 Coding Examples
Example 1
Clinical Scenario: A 64-year-old male with unilateral vocal cord paralysis following thyroidectomy presents for direct laryngoscopy with injection augmentation using a temporary filler. The procedure is performed under general anesthesia without microscope assistance. No other procedures are performed in the same session.
| Field | Code | Rationale |
|---|---|---|
| CPT | 31570 | Direct laryngoscopy with therapeutic injection, unaided visualization, matches the documented technique. |
| PDx | J38.01 | Unilateral vocal cord paralysis is the specific, documented indication for the injection. |
Note
Confirm the operative note explicitly states “direct laryngoscopy” and does not mention microscope or telescope use — if magnification was used, 31571 would be the correct code instead.
Example 2
Clinical Scenario: A 52-year-old female with spasmodic dysphonia undergoes direct laryngoscopy with botulinum toxin injection into the thyroarytenoid muscles bilaterally. A separate, significant E/M evaluation is also documented for a new complaint of dysphagia unrelated to the laryngeal condition.
| Field | Code | Rationale |
|---|---|---|
| CPT 1 | 31570 | Direct laryngoscopy with bilateral therapeutic injection — billed once per the bilateral indicator of 2, not twice. |
| CPT 2 | 99213--25 | Separately identifiable E/M for the new dysphagia complaint, modifier -25 appended to the E/M code (not to 31570) to indicate it was significant and separate from the injection procedure. |
| PDx | J38.3 | Spasmodic dysphonia falls under “Other diseases of vocal cords” per ICD-10-CM Alphabetic Index. |
Warning
Verify the local LCD for botulinum toxin injections (e.g., Noridian L33274) is met before submission — insufficient documentation of a qualifying indication is a leading denial reason for this drug/procedure combination.
Example 3
Clinical Scenario: A 71-year-old male with a history of glottic squamous cell carcinoma status post partial laryngectomy returns for injection augmentation of the residual vocal cord to improve post-surgical glottic closure. Direct laryngoscopy without magnification is used.
| Field | Code | Rationale |
|---|---|---|
| CPT | 31570 | Direct laryngoscopy with therapeutic injection matches the documented unaided technique. |
| PDx | C32.0 | Glottic malignancy remains the underlying etiology driving the post-surgical vocal cord dysfunction being treated. |
Global period reminder, if applicable
Since 31570 carries a 000-day global period, any follow-up visit the next day for a related concern is separately billable — there’s no 10- or 90-day postoperative bundling window to track here.
⚠️ Common Coding Pitfalls
- Pitfall 1: Selecting 31570 when the operative note actually describes a percutaneous (through-the-neck) injection rather than a transoral laryngoscopic approach. This misrepresents the technique entirely and the correct code is the unlisted procedure code 31599 with supporting documentation instead.
- Pitfall 2: Failing to distinguish 31570 from 31571 based on whether an operating microscope or telescope was used — this single documentation detail changes the correct code and is one of the most frequently audited distinctions in laryngology billing.
- Pitfall 3: Appending modifier -50 for a bilateral vocal cord injection. Because the code’s bilateral indicator is 2, the descriptor’s “(s)” already accounts for unilateral or bilateral injection at the same payment rate — modifier -50 doesn’t apply and won’t increase reimbursement.
- Pitfall 4: Billing 31570 twice on the same date to reflect two separate cords injected. This is one procedure regardless of how many cords are treated in the same session; report a single unit.
- Pitfall 5: Omitting laterality specificity on the paired ICD-10-CM code (defaulting to J38.00 instead of J38.01/J38.02) when the operative documentation clearly states which side is affected — this is a common CDI query trigger.
- Pitfall 6: Missing the LCD medical necessity documentation requirement when botulinum toxin is the injected agent, particularly around prior authorization for the HCPCS drug code — this is a leading cause of denials distinct from the procedure code itself.
📎 Sources
1. Find-A-Code. *CPT® Code 31570 — RVUs, Fees, and Payment Information.* InnoviHealth Systems Inc; 2026. https://www.findacode.com/cpt/31570-cpt-code.html 2. OpenPayer. *CPT 31570 Laryngoscopy Vocal Cord Injection Reimbursement.* 2026. https://www.openpayer.com/billing-codes/cpt-31570-laryngoscopy-with-vocal-cord-injection 3. Coding Ahead. *CPT® Code 31571.* 2026. https://www.codingahead.com/cpt/codes/31571 4. Comparing Utilization of Operative versus Awake Laryngoplasty Techniques in the United States Medicare Population: 22-Year Trends. PMC; 2025. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12574623/ 5. AAPC. *You Be the Coder: Coding for Percutaneous Vocal Cord Injection.* My Otolaryngology Coding Alert; 2015. https://www.aapc.com/codes/coding-newsletters/my-otolaryngology-coding-alert/you-be-the-coder-coding-for-percutaneous-vocal-cord-injection-145235-article 6. CMS Medicare Coverage Database. *Billing and Coding Guidelines for Botulinum Toxin Type A — LCD L28555/L33274 attachment.* https://downloads.cms.gov/medicare-coverage-database/lcd_attachments/28555_43/L28555_INJ018_CBG_010112.pdfSources 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.