What Is CPT Code 31575?
CPT code 31575 is the procedure code for a diagnostic flexible fiberoptic laryngoscopy, a minimally invasive examination where a thin, flexible scope is passed through the nose to visualize the larynx, vocal cords, and surrounding structures. It is one of the highest-volume diagnostic procedure codes in ENT practice and a frequent audit target for same-day E/M overbilling.
Quick Answers
It is diagnostic only: CPT 31575 covers visualization and diagnosis of the larynx. It is not a surgical procedure. If a therapeutic intervention such as a biopsy or lesion removal is performed during the same session, a separate surgical laryngoscopy code applies, and 31575 should not be reported alongside it.
Modifier 25 is the critical billing issue: When a separate E/M visit is billed on the same day as 31575, modifier 25 must be appended to the E/M code, and the documentation must support a significant, separately identifiable evaluation beyond the decision to perform the scope.
Medicare reimburses approximately $124 in office settings: The 2026 national average Medicare non-facility reimbursement for 31575 is approximately $123.89, based on the current conversion factor and the code’s total RVUs. Actual payment varies by geographic locality.
Is CPT Code 31575 a Surgical Procedure?
No. CPT 31575 is a diagnostic procedure, not a surgical one. It covers the visual examination of the larynx using a flexible fiberoptic scope and does not include any therapeutic intervention. The code descriptor is explicitly “Laryngoscopy, flexible; diagnostic,” which means it is limited to visualization, assessment, and interpretation of findings.
This distinction matters for billing because diagnostic and surgical laryngoscopy codes cannot be reported together when the surgical code already includes the diagnostic component. If a provider performs a diagnostic laryngoscopy and then proceeds to a surgical intervention such as a biopsy (31576) or lesion removal (31578) in the same session, only the surgical code is reported. Billing 31575 alongside a surgical laryngoscopy code is an unbundling error that triggers NCCI edit denials.
One question we hear constantly from ENT practice managers is whether 31575 should be reported when the scope reveals a finding that leads to a same-session surgical procedure. The answer is no. The diagnostic visualization is considered part of the surgical procedure’s work, and reporting both codes on the same date of service is a bundling violation. For a similar diagnostic-only code with its own bundling rules, see our guide to CPT code 31231 for diagnostic nasal endoscopy.
How to Bill 31575 with an E/M Visit on the Same Day
Billing a separate E/M service alongside CPT 31575 on the same date is permitted, but it requires modifier 25 on the E/M code and documentation that supports a significant, separately identifiable evaluation. This is the single most common billing issue on 31575, and it is also one of the most audited.
Modifier 25 goes on the E/M code (such as 99213 or 99214), not on 31575. The modifier tells the payer that the physician performed an evaluation that stands on its own, beyond the pre-procedure assessment that is inherent to performing the laryngoscopy. The E/M documentation must describe a distinct history, examination, or medical decision-making component that would justify a separate office visit even if the scope had not been done.
The scenario where modifier 25 is correct: a new patient presents with hoarseness. The provider performs a detailed history and physical examination, considers the differential diagnosis, and decides to perform a flexible laryngoscopy to visualize the vocal cords. The E/M visit is separately identifiable because the clinical evaluation preceded and independently justified the procedure.
The scenario where modifier 25 is incorrect: a patient returns for a scheduled follow-up scope to monitor a known vocal cord lesion. No new history is taken, no separate medical decision-making occurs, and the visit consists entirely of the laryngoscopy. Billing an E/M service with modifier 25 in this scenario is overcoding and a frequent audit finding.
Across the billing companies we vet for ENT practices, modifier 25 overbilling on laryngoscopy claims is the single most common compliance risk we see flagged during practice assessments. The error is rarely intentional. It typically reflects a billing workflow that automatically appends an E/M code to every procedure visit without verifying that the documentation supports it.
Modifier 25 errors on codes like 31575 are one of the most audited billing patterns in ENT, and the proposed CMS 2027 modifier 25 payment reduction would cut reimbursement on same-day E/M visits by 50%. If your practice bills laryngoscopy alongside office visits regularly, a billing partner with ENT-specific audit experience can identify where your documentation supports modifier 25 and where it does not. Get matched with vetted ENT billing companies, free.
How Does 31575 Differ from Related Laryngoscopy Codes?
The laryngoscopy code family was revised in January 2023, adding new codes and refining the distinction between rigid and flexible procedures. Understanding which code applies prevents bundling denials and ensures accurate reimbursement.
| CPT Code | Description | Key Distinction |
| 31575 | Laryngoscopy, flexible; diagnostic | Flexible scope, diagnostic visualization only |
| 31576 | Laryngoscopy, flexible; with biopsy | Flexible scope with tissue biopsy |
| 31578 | Laryngoscopy, flexible; with removal of lesion | Flexible scope with therapeutic lesion removal |
| 31579 | Laryngoscopy, flexible or rigid; with stroboscopy | Includes stroboscopic assessment of vocal fold vibration |
| 31571 | Laryngoscopy, rigid; diagnostic | Rigid telescope, diagnostic visualization |
The most important rule: 31575 cannot be billed alongside 31579 (stroboscopy) in the same session. CPT 31579 already includes the diagnostic component, so reporting both is a bundling violation. Similarly, 31575 bundles into 31576 or 31578 when a surgical intervention follows the diagnostic visualization in the same encounter.
In our experience matching ENT providers with billing partners, the 31575/31579 bundling error appears more often than any other laryngoscopy coding mistake. The provider performs a stroboscopy and the billing team reports both 31575 and 31579, generating a denial that could have been avoided with a single code selection. For practices that also perform tympanostomy tube procedures under CPT 69436, the same principle applies: know which codes bundle before submitting.
What Documentation Does 31575 Require?
Complete documentation for a 31575 claim must demonstrate why the procedure was performed, what was found, and that the scope type matches the code descriptor. Missing any of these elements exposes the claim to denial or post-payment audit.
Indication for the procedure: Document the clinical reason for the laryngoscopy, such as hoarseness, dysphagia, chronic cough, suspected vocal cord paralysis, laryngeal mass, or airway evaluation. The indication must match the ICD-10 code submitted.
Scope type: The note must specify that a flexible fiberoptic laryngoscope was used. CPT 31575 does not apply to rigid laryngoscopy or indirect mirror examinations.
Structures visualized: Document which anatomical structures were examined, including the base of tongue, epiglottis, arytenoids, vocal cords, subglottic region, and any other structures relevant to the clinical question.
Findings: Record all normal and abnormal findings, such as vocal cord mobility, mucosal lesions, edema, erythema, pooling of secretions, or structural abnormalities.
Clinical interpretation: Include a diagnostic impression signed by the examining provider, such as bilateral vocal cord nodules or left vocal cord paresis.
Separate E/M documentation (if billing modifier 25): If a same-day E/M is billed, the E/M note must document a separately identifiable history, exam, or medical decision-making component that goes beyond the standard pre-procedure assessment for the laryngoscopy.
For ENT practices that routinely bill comprehensive audiometry under CPT 92557 on the same day as a laryngoscopy visit, the documentation standard for each service must stand independently. A combined note that does not clearly delineate the work for each procedure invites payer scrutiny.
Common 31575 Denials and Fixes
Flexible laryngoscopy is one of the most frequently performed and most frequently denied diagnostic procedures in ENT. The denial patterns are predictable, and each one has a process-level fix.
Modifier 25 without supporting documentation. An E/M visit billed same-day with 31575 but the note does not document a separately identifiable evaluation. Fix: verify that the E/M documentation describes distinct history, exam, or MDM before appending modifier 25.
Unbundling with surgical laryngoscopy. Billing 31575 alongside 31576, 31578, or 31579 when the diagnostic component is already included in the surgical code. Fix: report only the most comprehensive code performed in the session.
Bundling with nasal endoscopy. Billing 31575 and 31231 together on the same day without documentation establishing that each procedure addresses a distinct clinical question. Fix: document separate indications for each scope and append modifier 59 or XS to the secondary procedure if the services are truly distinct.
Missing or unspecified diagnosis code. Using R49.0 (dysphonia) without laterality or specificity when a more precise code is available. Fix: code to the highest specificity the documentation supports.
Frequency limits. Some payers impose frequency limits on diagnostic laryngoscopy, particularly for follow-up scopes on the same condition. Fix: check payer-specific frequency policies before scheduling repeat procedures.
Incomplete documentation. Failing to specify the scope type (flexible vs. rigid) or omitting the interpretation. Fix: build a documentation template that requires all elements before the note is signed.
The biggest issue we see ENT providers run into is treating 31575 as a code that can be added to every office visit without scrutiny. It cannot. Every claim needs documentation that independently supports both the procedure and, if applicable, the separate E/M service. Providers often come to us after an audit flags a pattern of modifier 25 overuse, and the fix is almost always a documentation workflow adjustment, not a coding change.
Frequently Asked Questions
What is CPT code 31575?
CPT code 31575 is the procedure code for a diagnostic flexible fiberoptic laryngoscopy. It covers the insertion of a flexible scope through the nose to examine the larynx, vocal cords, and surrounding structures for diagnostic purposes. It does not include any surgical or therapeutic intervention.
Is CPT 31575 a surgical procedure?
No. CPT 31575 is strictly a diagnostic procedure. The code descriptor specifies “diagnostic,” meaning it covers only visualization and interpretation. If a surgical intervention such as a biopsy or lesion removal is performed during the same session, a separate surgical laryngoscopy code applies, and 31575 is not reported.
Can you bill an office visit with 31575 on the same day?
Yes, but only when the E/M visit is significant and separately identifiable from the laryngoscopy. Modifier 25 must be appended to the E/M code, and the documentation must support a distinct evaluation beyond the pre-procedure assessment inherent to performing the scope.
What is the difference between CPT 31575 and 31579?
CPT 31575 is a standard diagnostic flexible laryngoscopy. CPT 31579 is a laryngoscopy with stroboscopy, which uses a strobe light to assess vocal fold vibration patterns. The two codes cannot be billed together because 31579 already includes the diagnostic visualization component of 31575.
What is the Medicare reimbursement for 31575 in 2026?
The 2026 national average Medicare non-facility reimbursement for CPT 31575 is approximately $123.89, based on the current conversion factor and the code’s total relative value units. Actual payment varies by geographic practice cost index. In facility settings, the professional component is lower because practice expense is billed separately by the facility.
Can 31575 and 31231 be billed together?
Yes, but only when each procedure addresses a distinct clinical question and the documentation supports separate indications for each scope. Modifier 59 or XS is appended to the secondary procedure. If both scopes are performed for the same clinical complaint, billing both risks an unbundling denial.
What diagnosis codes support 31575?
Common ICD-10 codes paired with 31575 include dysphonia (R49.0), chronic laryngitis (J37.0), vocal cord paralysis (J38.00 through J38.02), laryngeal lesion (D14.1 or J38.1 through J38.3), dysphagia (R13.10 through R13.19), and chronic cough (R05.9). Use the most specific code the clinical documentation supports.
What modifiers are used with 31575?
The most commonly used modifier is 25 on the same-day E/M code. Modifier 59 or XS is used when 31575 is billed alongside another endoscopic procedure with distinct indications. Modifier 52 applies when the procedure was reduced or not fully completed. Modifier 76 is used for a repeat procedure by the same provider on the same day.
Next Steps
Need to review related ENT procedure codes? See our guides to CPT 31231 for diagnostic nasal endoscopy, CPT 69436 for tympanostomy tube placement, and CPT 92557 for comprehensive audiometry.
To learn how ENT Billing Services connects providers with billing partners who specialize in ENT coding, visit our About Us page.
Flexible laryngoscopy is one of the most frequently performed and most frequently audited diagnostic procedures in ENT, and modifier 25 compliance is the issue that trips up the most practices. If your billing team is generating preventable denials on 31575 claims or facing audit risk on same-day E/M billing, a specialized ENT billing partner can fix the workflow. ENT Billing Services has connected more than 2,000 providers across all 50 states with vetted billing companies, backed by over 15 years of medical billing expertise and rates starting as low as 2.95%. Getting matched is 100% free for providers.
