CPT code 46280 – Anal fistula surgery

Key takeaways

CPT Code 46280 covers fistulotomy or fistulectomy for transsphincteric, suprasphincteric, extrasphincteric or multiple anal fistulas.

Seton placement is included in 46280 when performed, so it is never billed as a separate line alongside this code.

The operative report must name the sphincter classification, or the payer cannot confirm 46280 over 46275 or 46270.

The 90-day global surgical period covers related post-operative care, and modifier 79 is required for unrelated procedures in that window.

Pabau’s claims management software tracks claim status and flags denial patterns at the code level, so billing teams can spot systemic 46280 rejections.

CPT Code 46280: Quick reference

CPT Code 46280 reports fistulotomy or fistulectomy for an anal fistula whose tract crosses, rises above, or bypasses the external sphincter, or for multiple tracts. Seton placement is included when performed.

The code sits in the Surgery section of the AMA’s code set, under the Anus subsection. Confirm it against the AMA’s CPT code set before billing.

What CPT Code 46280 covers

The code covers four tract classifications. Each one involves more of the sphincter complex than a subcutaneous fistula (46270) or an intersphincteric fistula (46275).

• Transsphincteric: The tract crosses through the external sphincter muscle at some level above the deep posterior anal canal. This is the most common classification billed under 46280.
• Suprasphincteric: The tract passes over the top of the puborectalis muscle before tracking downward. Less common and more technically demanding.
• Extrasphincteric: The tract bypasses the sphincter complex entirely, passing through the levator ani. These are the rarest and most complex.
• Multiple tracts: Two or more fistula tracts identified and treated in the same session. The descriptor names multiple tracts explicitly.
• Seton placement: Included in the descriptor when performed. A seton placed during the procedure does not generate a separate billable service.

A reliable medical billing workflow for colorectal surgery starts here. Confirm the sphincter classification from the operative note before the claim is submitted, rather than after the denial arrives.

46280 vs related anal fistula CPT codes

The anal fistula code family (46270-46288) is sorted by how deep the tract runs through the sphincter complex, with 46288 reserved for flap closure. Picking the wrong level changes both the payment and the documentation the payer expects to see.

Decision rule for coders: Code 46280 when the operative note documents a transsphincteric, suprasphincteric or extrasphincteric tract. Those tracts cross the external sphincter or pass above or around it. An intersphincteric fistula is coded 46275, never 46270. Reserve 46270 for a subcutaneous tract that stays outside the sphincter complex.

The chart below maps each documented finding to the one code it supports.

Is seton placement separately billable with CPT 46280?

No, seton placement is not separately billable when reported with CPT Code 46280. The AMA descriptor includes “placement of seton, when performed,” so NCCI edits bundle the seton service into the primary code.

Billing a separate seton code alongside 46280 triggers an NCCI bundling edit and an automatic denial of the secondary line. The operative report should still record that a seton was placed, its type (cutting or draining), and the clinical rationale. That detail supports the complexity of 46280 rather than a separate charge.

Documentation requirements for CPT 46280

Payers scrutinize anal fistula surgery claims because code selection (46270, 46275 or 46280) hinges on intraoperative findings that only appear in the operative report. A weak op note is the main driver of downcoding and denial.

The operative report must address each of the following to support a 46280 claim. Accurate superbill documentation captures these elements at the point of service, before the claim is built.

• Sphincter classification: Name it explicitly. “Transsphincteric fistula” is sufficient. “High fistula” or “complex fistula” without anatomical specificity is not.
• Surgical approach: State whether fistulotomy or fistulectomy was performed and why the approach was chosen given the tract anatomy.
• Seton use: Document seton type (cutting/draining), placement site, and rationale if a seton was used.
• Number of tracts: If multiple tracts were identified and treated, each should be described. Multiple tracts support 46280 over simpler codes.
• Surgeon attestation: The operating surgeon must sign and date the report. Many payer policies don’t accept a mid-level supervision note for complex anorectal procedures.

Submitting a clean claim for CPT Code 46280 depends on capturing this detail before the encounter closes. Re-querying the surgeon after the claim is built adds days to the revenue cycle. It may still not produce a complete note if documentation habits aren’t set upfront.

Supported ICD-10-CM diagnosis codes

Medical necessity for CPT Code 46280 requires a matching ICD-10-CM diagnosis code. The table below lists the primary codes accepted by most payers for FY2026.

Use the most specific code the documentation supports. K60.3 is the preferred starting point for fistula-in-ano. Submitting K60.5 when K60.3 is clearly supported may prompt a payer specificity edit on some commercial plans.

Modifiers for CPT Code 46280

Modifier use on CPT Code 46280 follows standard surgical modifier rules. The most common questions involve multiple procedures, return-to-OR scenarios, and services performed during the 90-day global period.

Modifier 59 requires particular care. The AAPC notes that overuse of Modifier 59 to unbundle otherwise bundled services is a documented OIG scrutiny area. Only append it when the operative record clearly supports two distinct services performed for separate clinical indications.

Reimbursement and fee schedule for CPT 46280

Medicare reimbursement for CPT Code 46280 is calculated from the Relative Value Units (RVUs) published in the annual Medicare Physician Fee Schedule (MPFS).

The 2026 national rates below are not geographically adjusted, and payment varies by locality. Use the CMS Physician Fee Schedule lookup tool to pull site-specific and facility vs. non-facility rates for your practice location.

The CY2026 Medicare conversion factor is $33.40, or $33.57 for qualifying APM participants. At $33.40, the non-facility national rate comes to roughly $590 and the facility rate roughly $425. These figures are unadjusted estimates, and the FastRVU 2026 RVU lookup applies your geographic practice cost index and produces locality-specific payment amounts.

Private payer rates vary by contract. As a general industry estimate, commercial rates may run 110-150% of Medicare, though contract rates differ widely by payer and geography. Pabau’s Claim.MD clearinghouse integration handles eligibility checks and electronic remittance for CPT Code 46280 claims across thousands of US payers.

The 90-day global surgical period means that follow-up office visits related to the fistula repair are bundled into the procedure payment for three months post-surgery. Use Modifier 24 to bill an evaluation and management service for an unrelated condition during that window. Use Modifier 79 for a wholly unrelated surgical procedure.

Tracking the global period end date is where claims management software earns its keep. A missed end date means either a denied claim or an overbilling risk.

Prior authorization for anal fistula surgery

Many commercial payers, including Anthem, UnitedHealthcare, and Cigna plans, require prior authorization for elective anal fistula surgery. When authorization is required and missing, the payer can deny the entire claim.

Requirements vary by payer and plan, so check the plan’s portal before you schedule. Most commercial criteria share the same elements, and a documented prior authorization process keeps staff from rebuilding them case by case.

• Failed conservative management: Documentation of prior treatment that did not resolve the fistula, such as antibiotics, drainage of an associated abscess, fiber, and sitz baths.
• Imaging or examination confirmation: Endoanal ultrasound, MRI of the pelvis, or examination under anesthesia confirming the fistula tract and sphincter classification.
• Specialist credentials: Most payers require the operating surgeon to be a board-eligible or board-certified colorectal surgeon or general surgeon with documented anorectal experience.
• ICD-10 specificity: The authorization request must include the correct ICD-10-CM code (K60.3, K60.4, or K60.5) with clinical notes supporting the classification.

Emergency presentations, such as an acute abscess with fistula that needs urgent drainage, are generally exempt from elective prior authorization. The clinical urgency still has to be documented. Retroactive authorization requests for emergent cases have a low approval rate unless the operative note clearly establishes urgency.

Common claim denial reasons for CPT 46280

CPT Code 46280 denials cluster around three root causes: code selection errors, missing documentation, and bundling violations. Each has a distinct appeal path and a specific documentation fix.

1. Insufficient sphincter classification documentation. The operative report uses “high fistula” or “complex fistula” without naming the anatomical classification. The payer cannot confirm 46280 over 46275 or 46270. Appeal with a surgeon attestation letter naming the specific sphincter level and clarifying the operative findings. Implement a post-op note checklist that requires the sphincter classification field before the note is signed.
2. Wrong code selected, with 46270 billed when 46280 is warranted. Coders without colorectal specialty training default to 46270. The claim pays at a lower rate, and if the error is caught on audit, it triggers a recoupment request. Review ops reports for the keywords “transsphincteric,” “suprasphincteric,” or “extrasphincteric” before finalizing code selection.
3. Seton billed separately. A separate seton line triggers the NCCI bundle edit automatically. Remove the separate seton charge on appeal, leaving 46280 as the sole code for the encounter.
4. Non-specific ICD-10-CM code. An unspecified or mismatched diagnosis code leaves medical necessity unsupported. Match the ICD-10-CM code to the documented fistula type. K60.3 for anal, K60.4 for rectal, K60.5 when the op note supports anorectal without further distinction.
5. Prior authorization not obtained for elective cases. When the payer requires prior authorization and none was obtained, an appeal rarely succeeds. Most payers won’t approve retroactive authorization without strong documentation of urgency.
6. Global period violation. Billing a related service within 90 days of the procedure date without the correct modifier. Use Modifier 78 for complications, 79 for unrelated procedures, and 24 for unrelated E&M visits.

Effective denial management for CPT Code 46280 tracks rejections at the code level as well as the account level. If 40% of your 46280 denials share the same remark code, one template change fixes them faster than 40 separate appeals. Knowing the denial codes in medical billing helps billing teams respond faster.

How claims management software protects CPT 46280 reimbursement

In many colorectal practices, the billing team learns that a sphincter classification is missing only when the denial arrives. By then the surgeon has moved on to other cases, and the re-query adds days to the revenue cycle.

Pabau’s practice software keeps the operative note, the diagnosis code and the claim in the same patient record. Coders check the documented tract level before the 46280 claim goes out, and claims management follows it through to remittance.

Denials are grouped by code, so a run of documentation rejections on 46280 points to the note template rather than to one bad claim. That turns revenue cycle management for colorectal surgery into fixing causes instead of chasing appeals.

Reduce anal fistula claim denials with integrated billing

Pabau connects clinical documentation and claims management in one workflow. Sphincter classification and ICD-10 codes are captured at the point of care, before a denial forces a re-query.

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Conclusion

For CPT Code 46280, the coding decision is effectively made in the operating room. If the surgeon names the tract level in the op note, the code, the diagnosis and any appeal all follow from it.

So the change worth making sits upstream of billing. Make the sphincter classification a required field in the post-op note, and check NCCI pairs and global period dates before submission. It asks a little more of the surgeon per case, and that costs far less than a run of appeals.

Book a demo to see how Pabau links operative notes to claims, so your 46280 claims go out complete the first time.

Continue your research

Need to verify eligibility before submitting a 46280 claim? Insurance eligibility verification covers how to confirm patient coverage and authorization status before the procedure date.

Tracking 835 remittances for your surgical claims? Electronic remittance advice explains how to read ERA files and match payment postings to 46280 claim lines.

Want to understand how clearinghouse submission works? 837 file submission walks through the electronic claim format used to transmit CPT 46280 claims to Medicare and commercial payers.

Frequently asked questions