CPT code 46275 – Intersphincteric anal fistulotomy and fistulectomy

Key takeaways

CPT code 46275 reports fistulotomy or fistulectomy for an intersphincteric anal fistula, a tract that runs between the internal and external sphincters.

A subcutaneous tract goes to 46270, while transsphincteric, suprasphincteric, extrasphincteric or multiple fistulas, and seton placement, go to 46280.

For 2026, CMS gives 46275 a work RVU of 5.28, 12.73 total facility RVUs and a 90-day global period.

The operative report must name the tract as intersphincteric and say which sphincter fibers were divided, or the claim can’t defend the code.

Pabau’s claims management software, integrated with the Claim.MD clearinghouse, scrubs 46275 claims for NCCI edits and payer rules before submission.

CPT code 46275: Official description and procedure overview

CPT code 46275 describes “Surgical treatment of anal fistula (fistulectomy/fistulotomy); intersphincteric,” according to the AMA’s CPT code set. CMS lists it under the short descriptor “Remove anal fist inter.” It is a Category I surgical code maintained by the AMA CPT Editorial Panel.

An intersphincteric fistula runs from the anal canal through the internal sphincter, then down the plane between the two sphincters to the perianal skin. It doesn’t cross the external sphincter, and that anatomy is what earns 46275.

The code covers both fistulotomy (laying the tract open) and fistulectomy (excising it), so the surgeon’s choice between the two doesn’t change it. What changes the code is where the tract runs: A subcutaneous tract is 46270, and one crossing the external sphincter is 46280.

Procedure details: What happens during a 46275 fistulotomy

Fistulotomy for an intersphincteric fistula follows a consistent sequence. Coders need this clinical context to match the operative note against the descriptor, and to spot a case that belongs to 46270 or 46280 instead.

1. Examination under anesthesia: The patient is placed in prone jackknife or lithotomy position. The surgeon examines the anal canal and identifies the external and internal openings.
2. Tract probing: A probe is passed along the tract to map its course. Hydrogen peroxide or dilute methylene blue may be injected to confirm the internal opening.
3. Sphincter assessment: The surgeon confirms the tract crosses only the internal sphincter and stays inside the external sphincter. A tract that crosses the external sphincter moves the case to 46280.
4. Laying open or excision: The surgeon divides the overlying skin and the internal sphincter fibers to lay the tract open, or excises the tract entirely. The external sphincter is preserved.
5. Wound management: The tract is curetted, and the edges are marsupialized or left to heal by secondary intention.

The operative report must mirror this sequence. A note that states only “fistulotomy performed,” without naming the tract’s relation to the sphincters, leaves the payer free to treat the case as 46270.

CPT 46275 vs 46270 and 46280: Choosing the right code

The anal fistula series sorts codes by where the tract runs relative to the sphincter muscles. Picking the wrong level is the most common reason a 46275 claim is recoded on review.

Two findings move a case out of 46275 entirely. If the surgeon treats more than one fistula or places a seton, report 46280, whose descriptor includes multiple fistulas and seton placement when performed. The chart below puts those checks ahead of the tract’s path.

When 46040 and 46275 are both performed at the same operative session, check the NCCI edits before reporting them together. Modifier 59 may allow separate billing, but only when the abscess and the fistula are anatomically distinct and each is fully documented.

ICD-10 diagnosis codes that support CPT 46275 claims

Current ICD-10-CM splits anal fistula (K60.3) into simple and complex subcategories, each with a sixth character for initial, persistent, recurrent or unspecified. Report the most specific code available, because the K60.3 header alone isn’t billable. Use K60.30 (anal fistula, unspecified) when the note doesn’t call the fistula simple or complex.

The simple/complex axis in ICD-10-CM is a clinical label, and it doesn’t pick the CPT code. If the surgeon calls an intersphincteric fistula complex, the diagnosis can be K60.32- while the procedure stays 46275, because CPT follows the tract’s anatomy.

Verify the subcategory list against the ICD-10-CM tabular list for the claim’s date of service before submitting. Payer crosswalk tables vary, and a commercial payer’s system may lag behind the current code set.

Medicare reimbursement and RVUs for CPT code 46275

CPT code 46275 carries a 90-day major surgery global period under the CMS Physician Fee Schedule. The 2026 values below come from the CMS PPRRVU file as listed on FastRVU. Payment varies by locality, so confirm current figures in the Medicare Physician Fee Schedule (MPFS) Look-Up Tool before fee negotiations or budget planning.

The national payment figures use the 2026 conversion factor of $33.4009. For comparison, 46270 carries a 2026 work RVU of 4.80 and 46280 carries 6.23.

The 0.48 step down to 46270 and the 0.95 step up to 46280 are why the anatomy in the note matters to payment. Most 46275 procedures occur in an ASC or hospital outpatient setting, so the surgeon is paid at the facility rate. The facility bills separately under the CMS Outpatient Prospective Payment System (OPPS) or the ASC payment system.

Use the FastRVU lookup tool or the CMS MPFS Look-Up to retrieve current-year locality-adjusted rates before contracting or fee schedule analysis.

Prior authorization requirements for fistulotomy

Many commercial payers and Medicare Advantage plans require prior authorization for CPT 46275, though requirements vary by payer and plan year. There is no universal rule, so verify with the specific payer before scheduling the procedure.

When prior authorization is required, payers typically ask for this documentation:

• Clinical notes on conservative management: Some payers want evidence that symptoms persisted despite treatment, such as abscess drainage and wound care, before approving surgery.
• Imaging or examination findings: Pelvic MRI or endoanal ultrasound showing the tract in the intersphincteric plane supports medical necessity and the code choice.
• Surgeon’s operative plan: A brief letter from the operating colorectal surgeon describing the planned approach, the tract anatomy, and the expected setting (ASC vs hospital).
• ICD-10 diagnosis codes: List the most specific anal fistula code, such as a K60.31- or K60.32- code. The payer runs its medical necessity logic against it.

A denial for missing prior authorization (CO-197) is preventable. A medical claims clearinghouse with eligibility verification can flag auth requirements at scheduling rather than at claim submission. Build the auth check into your intake workflow for every scheduled colorectal surgery case rather than relying on the surgeon’s office to flag it.

Modifiers and NCCI bundling edits for CPT 46275

Several modifiers apply to CPT 46275 depending on operative circumstances. The National Correct Coding Initiative (NCCI) also defines column-1/column-2 pairs that govern what can be billed alongside 46275 in the same session.

Dividing the internal sphincter fibers that the tract crosses is part of laying an intersphincteric fistula open. That division is included in 46275, so reporting a separate sphincterotomy code for the same muscle invites an NCCI denial.

Verify the current NCCI edits via the AAPC Codify tool or the CMS NCCI Policy Manual before submitting combined claims, since bundling pairs change quarterly. Checking the edit tables every quarter is part of medical billing compliance, so give the task a named owner.

Documentation requirements for the operative report

The operative report is the only document that defends CPT 46275 against a recoding challenge. Payers and Recovery Audit Contractors (RACs) routinely pull operative notes for anorectal surgery claims, and a thin note is a fast denial.

Every operative report supporting a clean claim submission for 46275 should contain these elements:

• Fistula classification: Name the tract as intersphincteric, using the Parks classification or equivalent wording. That one word separates 46275 from 46270 and 46280.
• Sphincter involvement: State that only internal sphincter fibers were divided and that the external sphincter was preserved. A note with no sphincter language makes 46270 look like the correct code.
• Number of fistulas: Confirm that a single fistula was treated. If the surgeon treated more than one, the case belongs to 46280.
• Seton use: Record whether a seton was placed. If one was, report 46280, which includes seton placement when performed.
• Technique narrative: Include probe findings, dye injection results, whether the tract was laid open or excised, and how the wound was managed.
• Findings on examination under anesthesia: Record the external and internal openings, the tract’s course, and any secondary extensions.

Top denial reasons for CPT 46275 claims

Denials on CPT 46275 cluster around a short list of root causes, most of which are preventable. A structured denial management workflow that traces each claim adjustment reason code (CARC) back to an upstream documentation or authorization failure reduces rework.

For what each code means across specialties, see our denial code reference. Tracking 46275 denials by CARC each month shows whether a new NCCI edit or payer policy is driving a spike. That lets you fix the cause before it turns into a backlog.

How claims management software prevents 46275 denials

Billing CPT 46275 accurately takes three moving parts: A complete operative report, a verified prior auth, and a claim that passes NCCI edit checks. Manual workflows fail at any of those three points. A practice management system with built-in claims management software runs that scrub automatically, so denials are caught before submission rather than after adjudication.

Pabau’s billing software sends claims through its Claim.MD clearinghouse integration, which submits electronic CMS-1500 claims to thousands of US payers. It also runs real-time eligibility checks and posts electronic remittance advice (ERA) files with their claim adjustment reason codes.

For a colorectal surgery practice billing 46275 regularly, eligibility problems surface at scheduling and NCCI edit warnings appear before the claim goes out. When a denial does come back, the CARC on the ERA tells your team which documentation or authorization step to fix.

If you’re tracing where a surgical practice loses revenue before claims reach the clearinghouse, start with the full medical billing workflow around the coding step.

Reduce 46275 claim denials with Pabau

Pabau’s integrated claims workflow checks payer rules, runs eligibility checks and submits clean claims through the Claim.MD clearinghouse. Your billing team spends less time reworking 46275 denials.

Book a demo

Conclusion

The most preventable source of CPT 46275 revenue loss is an operative note that never says where the tract ran. Without the word “intersphincteric” and a statement on sphincter division, a payer can recode the case to 46270 or deny it.

The opposite error costs just as much. A case with multiple fistulas or a seton belongs to 46280, and billing it as 46275 leaves 0.95 work RVUs unclaimed. Make tract anatomy the first question in your coding review, and the right code follows from the note.

Is your billing team spending more time on 46275 rework than on new claims? Book a demo to see how Pabau catches these errors before submission.

Continue your research

Need to understand how clearinghouse claim submission works? Claim.MD clearinghouse overview explains how electronic claim routing, ERA posting, and real-time eligibility verification work together in a surgical billing workflow.

Want to see how a surgical claim is structured electronically? 837 file submission guide covers how the 837P transaction set structures surgical claims and where formatting errors trigger preventable rejections.

Billing the same procedure for a UK private patient? CCSD code H5510 covers laying open a low anal fistula in the UK private-insurer code set.

Want to verify payer eligibility before scheduling fistulotomy? Insurance eligibility verification walks through how real-time eligibility checks confirm coverage and prior auth requirements before the patient arrives.

Frequently asked questions