CPT Code 31624: Bronchoscopy with bronchial alveolar lavage

CPT Code 31624 is a bronchoscopy procedure code that covers bronchial alveolar lavage (BAL), including fluoroscopic guidance when performed. Pulmonologists and respiratory care teams use it to report saline instilled into a targeted lung segment. The aspirated fluid then goes to the laboratory for analysis.

According to the American Medical Association, CPT Code 31624 sits within the endoscopy procedures on the trachea and bronchi subsection of the Respiratory System. In 2026, Medicare pays roughly $286 for the code in an office and roughly $121 in a hospital or ambulatory surgical center.

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Key takeaways

CPT Code 31624 describes rigid or flexible bronchoscopy with bronchial alveolar lavage, distinct from the diagnostic-only base code 31622.

The 2026 Medicare non-facility rate is roughly $286 and the facility rate is roughly $121, though amounts vary by geographic locality.

The practice expense RVU creates that difference, which makes a place-of-service error one of the costliest mistakes on this code.

Modifier 59 is the most frequently required modifier, and modifier 52 applies only when the BAL is abandoned before sample collection.

Pabau links clinical documentation to the billing workflow, so bronchoscopy claims carry the detail payers ask for.

CPT Code 31624: Official description and clinical context

CPT Code 31624 is defined by the AMA as: Bronchoscopy, rigid or flexible, including fluoroscopic guidance, when performed; with bronchial alveolar lavage.

The phrase “when performed” means fluoroscopic guidance is optional. Where it is used, this code already captures it, so it cannot be billed separately.

The code sits in CPT section 31615-31654, which covers endoscopy of the trachea and bronchi. It applies to both rigid and flexible bronchoscope approaches. The defining clinical feature is the lavage. Saline is instilled into one or more lung segments and aspirated back, collecting cells and fluid for analysis.

What happens during bronchial alveolar lavage

Bronchial alveolar lavage is a diagnostic and therapeutic procedure performed through a bronchoscope. The physician advances the scope into the airway until it wedges into a subsegmental bronchus. Sterile saline is then instilled in aliquots, typically 20-60 mL per wash, and aspirated back into a collection trap.

The collected fluid contains cells, microorganisms, proteins, and particulate matter from that lung region. Laboratory analysis can identify bacteria, fungi, mycobacteria, malignant cells, and markers of inflammatory or fibrotic lung disease. BAL is commonly used to investigate suspected infection, interstitial lung disease, and pulmonary malignancy.

• Step 1: Patient is sedated; the bronchoscope is passed transnasally or transorally into the airway
• Step 2: Scope is advanced to the target subsegmental bronchus and wedged in place
• Step 3: Sterile saline is instilled in sequential aliquots and immediately aspirated
• Step 4: Aspirated fluid is collected and sent to the laboratory for cytology, culture, or cell differential
• Step 5: Scope is withdrawn, and the procedure note records the segments lavaged, the volumes instilled and recovered, and the clinical indication

CPT Code 31624 reimbursement rates and fee schedule

The CMS Physician Fee Schedule sets the Medicare payment rates for CPT Code 31624. Rates differ by place of service. Non-facility covers an office or outpatient practice, while facility covers a hospital or ambulatory surgical center. Geographic adjustment factors apply on top, so rates in San Francisco run meaningfully higher than rates in rural Mississippi.

Always verify current rates using the CMS Physician Fee Schedule Lookup Tool or your MAC’s jurisdiction-specific fee file. National averages are published in January and apply through December 31 of each year. Reading the remittance advice from each payer confirms what lands in the account for every 31624 claim.

Relative value units (RVUs) for CPT Code 31624

RVUs are the building blocks of Medicare payment. The FastRVU 2026 RVU lookup tool publishes current work, practice expense, and malpractice values for 31624. The table below shows each component in both places of service.

Work and malpractice RVUs stay the same in both settings. Practice expense does not, and that single component is why the office rate runs more than double the facility rate. Each total is then multiplied by the 2026 CMS conversion factor, which is $33.40 for clinicians outside an advanced APM and $33.57 for qualifying participants.

RVU values are updated annually in the CMS Final Rule. Verify against the current year’s published data rather than a prior-year figure, because both the component values and the conversion factor change.

Applicable modifiers for CPT Code 31624

Modifier errors sit among the top denial triggers on 31624 claims. The table below shows which modifier applies in each scenario, and what the operative note has to support.

Modifier 52 and incomplete bronchoscopy

The American Association for Bronchology and Interventional Pulmonology (AABIP) has issued position statement guidance on modifier 52 for bronchoscopy codes.

A bronchoscopy may be terminated early for patient tolerance, hemodynamic instability, or technical failure. Where that happens before the lavage sample is collected, modifier 52 tells the payer that a reduced service was delivered.

The operative note then has to document what was and was not accomplished. A note that reads “procedure incomplete” will not support the modifier. Four details belong in it:

• How far the scope advanced
• Which segment was targeted
• The reason for termination
• Whether any lavage fluid was collected

Without that specificity, payers will either deny the claim or apply an audit flag for review.

Documentation requirements for CPT Code 31624

Payers read the operative note before they pay a 31624 claim. Every element below should appear in that note before the claim is submitted. Payer policy asks for documentation that supports the code billed, not only the diagnosis.

• Clinical indication: The specific reason BAL was performed (e.g., suspected Pneumocystis jirovecii pneumonia, evaluation of interstitial lung disease, ruling out malignancy)
• Scope type and approach: Flexible or rigid; transnasal or transoral
• Segment(s) lavaged: Which bronchopulmonary segment received lavage (e.g., right middle lobe, lingula)
• Volume instilled and recovered: Total saline instilled and approximate volume recovered
• Fluoroscopy documentation: If fluoroscopy was used, confirm it in the note, because it is then included in 31624 and not separately billable
• Specimen handling: Where the aspirate was sent (microbiology, cytology, cell differential) and any labeling details
• Patient consent: Documented informed consent prior to the procedure
• Medical necessity: Supporting ICD-10-CM diagnosis code(s) that clinically justify the procedure

A structured procedure note template reduces the risk of a missing element. Where the note and the claim sit in one system, the claim cannot leave the practice before the record is complete.

CPT Code 31624 vs 31622: Choosing the correct code

CPT Code 31622 is the base diagnostic bronchoscopy code, while CPT Code 31624 adds bronchial alveolar lavage to that base procedure. The distinction matters for billing, because 31622 cannot be upgraded to 31624 by adding the word “lavage” to the note.

The most common coding error here is billing both 31622 and 31624 for the same session. Because 31624 includes the diagnostic bronchoscopy as part of the procedure, adding 31622 constitutes unbundling.

Related bronchoscopy CPT codes

CPT Code 31624 belongs to a family of bronchoscopy codes, each defined by the additional service performed during the scope. Reading the full family helps coders select the most accurate code and avoid undercoding or unbundling. The AAPC Codify CPT lookup carries the complete descriptor for each code in this range.

Bundling rules and NCCI edits for CPT Code 31624

The National Correct Coding Initiative (NCCI) administers the bundling edits that govern how bronchoscopy codes interact. Reading these edits before submission prevents the most costly claim errors in pulmonology billing.

The core bundling rule: 31622 (diagnostic bronchoscopy) bundles into 31624. When BAL is performed, 31624 is the correct and complete code. Bill both on the same date without a distinct clinical rationale, and the NCCI edit rejects the lower-valued code, typically 31622.

• 31622 + 31624 same date, same session: 31622 is bundled into 31624, so do not bill both
• 31623 + 31624 same session: Modifier 59 on 31623 may allow separate billing if a distinct bronchial brushing was performed at a separate location
• 31625 + 31624 same session: Modifier 59 on 31625 is generally accepted, and the note should document separate anatomical sites
• 31628 + 31624 same session: Frequently reviewed, and NCCI edits apply, so confirm with current CMS NCCI tables before billing
• Fluoroscopy codes separately: Never bill fluoroscopy guidance separately alongside 31624, because the descriptor already captures it

NCCI edits are updated quarterly, so the guidance here reflects general principles. Verify the current edit pair table through CMS before submitting claims. Building that check into the pre-submission workflow catches a bad pairing before the payer does.

ICD-10 codes commonly billed with CPT Code 31624

Medical necessity for CPT Code 31624 must be supported by a diagnosis code that clinically justifies bronchial alveolar lavage. The ICD-10-CM codes below are the most frequently paired diagnoses. Payer LCDs may specify approved diagnosis lists that differ by MAC jurisdiction.

The diagnosis usually sharpens once the lavage culture returns. A pneumonia coded to J18.9 before the procedure moves to J13 once the organism comes back as pneumococcus. The claim should then carry the specific code.

Always verify that the submitted ICD-10 code aligns with your MAC’s LCD for bronchoscopy. Some MACs publish accepted diagnosis lists that restrict coverage to particular codes. Submitting with a non-covered diagnosis is the fastest path to a medical necessity denial.

Common billing errors and denial reasons for CPT Code 31624

Bronchoscopy claims fail more often than a routine office visit, mostly on bundling and documentation. A workflow that reads the denial codes on each remittance catches the pattern before it turns into write-offs.

• Unbundling 31622 with 31624: Billing the base diagnostic code alongside the lavage code on the same date, with no distinct documented reason. Payers auto-bundle and reduce payment
• Missing lavage documentation: The note references BAL without naming the segment lavaged, the volume instilled, or the specimen disposition. That results in a documentation denial
• Incorrect modifier for an incomplete procedure: Modifier 52 is required when BAL was only partly completed. The note must document why the procedure ended early
• Non-covered diagnosis: Using an ICD-10 code the applicable MAC LCD does not support for bronchoscopy. Medical necessity denials are the hardest to appeal
• Separately billing fluoroscopy: Adding a fluoroscopy guidance code when fluoroscopy was used during 31624, which the descriptor already includes
• Place of service mismatch: Billing at the non-facility rate for a procedure performed in a hospital or ASC. Payers cross-reference place of service against facility claims

Catching these at submission rather than at appeal is what lifts first-pass resolution on bronchoscopy claims. Each denial avoided also removes a rework cycle from the billing team’s queue.

How billing software supports CPT Code 31624 claim accuracy

Manual bronchoscopy billing asks the coder to reconstruct the procedure from a dictated note. They then check NCCI edits in a separate reference tool, select modifiers from memory, and match ICD-10 codes to payer-specific LCDs. Each hand-off is a point where errors enter the claim.

Practice management software like Pabau closes those hand-offs. Pabau’s claims management software links the clinical record directly to the billing workflow. Procedure note templates can be configured to prompt for the elements that support a 31624 claim: segment lavaged, volume instilled, fluoroscopy use, and specimen disposition.

Claims then go out electronically through Claim.MD, Pabau’s integrated US clearinghouse, which reaches thousands of payers. Its built-in CPT and ICD-10 catalogs validate each claim before submission, so a missing modifier surfaces on screen rather than on a remittance.

Eligibility checks can run before the bronchoscopy date, so a non-covered diagnosis surfaces ahead of the procedure instead of weeks after it. Remittance posting then closes the loop from claim submission through payment, and the denial reasons land against the same patient record.

Reduce bronchoscopy claim denials with Pabau

Pabau links clinical documentation to the billing workflow, so the detail behind a CPT Code 31624 claim is captured at the point of care.

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Conclusion

Most of what goes wrong on a 31624 claim is decided before it is submitted. Two habits fix the bulk of it. Bill 31624 alone when lavage was performed, and make the operative note name the segment, the volume, and the specimen’s destination.

The place-of-service field deserves the same attention, because the office and facility rates sit about $165 apart on this code. Getting that field wrong costs more than any modifier error on the page.

Pabau’s integrated documentation and claims workflows remove the manual steps that introduce those errors. Book a demo to see how it handles bronchoscopy billing in a pulmonology or respiratory care practice.

Continue your research

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Worried about claim denials across your procedure codes? Denial codes in medical billing covers the most common CARC and RARC codes your team will encounter after a 31624 rejection.

Looking to understand how 837P files work for electronic claim submission? 837 file guide walks through the electronic claim transaction format used for professional claims including bronchoscopy codes.

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