Surgical release of the tarsal tunnel to decompress the posterior tibial nerve at the medial ankle.

Verified May 8, 2026 · 7 sources ↓

Medicare: $545.44
Total RVUs: 16.33
Global, days: 90
Region: Foot & ankle

Drawn from CMSAxogenincAAOSAAPC

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 7 cited references ↓

Operative note must name the specific nerve(s) decompressed — posterior tibial nerve, medial plantar, lateral plantar, or calcaneal branch.
Document the surgical approach: medial incision behind the medial malleolus with identification and release of the flexor retinaculum.
Pre-operative clinical findings supporting nerve compression: duration of symptoms, provocative signs (Tinel's), and failed conservative management.
If bilateral release performed, document each side separately with independent indications and intraoperative findings.
If additional neuroplasty (e.g., 64704) is billed same-day, document distinct nerve(s) addressed and anatomical separation from the primary tarsal tunnel release.
Global period exceptions: any unrelated E/M or procedure within 90 days post-op requires modifier 24 or 79 with supporting documentation.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 50 Bilateral procedure 51 Multiple procedures 57 Decision for surgery 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 28035 covers open tarsal tunnel release — decompression of the posterior tibial nerve and its branches by incising the flexor retinaculum at the medial ankle. The procedure addresses tarsal tunnel syndrome, where the tibial nerve is compressed within the fibro-osseous tunnel, producing plantar pain, paresthesias, and intrinsic weakness. The 90-day global period applies, covering all routine post-op care through day 90.

This is a unilateral code. When both ankles are released in a single operative session, modifier 50 is required — but payer conventions vary: some want the code listed once with modifier 50, others want two line items with LT and RT. Verify with each payer before submitting. NCCI edits bundle 64708 (major peripheral nerve neuroplasty) into 28035 when reported together, per CMS NCCI data — adding 64704 for separate nerve work on a distinct structure may be supportable with modifier 59 or XS, but document the distinct nerve and anatomical separation carefully.

The procedure is performed predominantly by podiatric surgeons. When an associated plantar fascia release (28008) is performed at the same encounter, modifier 51 applies to the secondary procedure. If the decision for surgery was made at the same visit, append modifier 57 to the E/M code — this is a 90-day global procedure, so modifier 57 is required (not 25).

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	5.1
Practice expense RVU	10.57
Malpractice RVU	0.66
Total RVU	16.33
Medicare national rate	$545.44
Global period	90 days

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

Setting	Medicare rate (national)
Office (PFS non-facility) Procedure performed in physician's office	$545.44
HOPD (APC 5431) Hospital outpatient department	$1,995.02
ASC (PI A2) Ambulatory surgical center (freestanding)	$948.66

Common denial reasons

The recurring reasons claims for CPT 28035 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

Bundling with 64708 — NCCI edits make major peripheral nerve neuroplasty a component of 28035 without a valid modifier and supporting documentation.
Bilateral procedure denied when modifier 50 is absent or payer requires LT/RT line items instead of a single code with modifier 50.
Medical necessity denied when pre-op documentation lacks evidence of failed conservative treatment or objective nerve compression findings.
Modifier 57 missing on the same-day E/M when the decision for this 90-day global procedure was made at that visit.
Incorrect diagnosis code pairing — tarsal tunnel syndrome must be the primary ICD-10 diagnosis; non-specific foot pain codes trigger medical necessity reviews.

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 7 cited references ↓

01Can 28035 and 64704 be billed together for the same operative session?

Potentially yes, but proceed carefully. NCCI bundles 64708 into 28035. If the surgeon separately addressed a distinct branch (e.g., a medial calcaneal branch neuroplasty as a distinct procedure from the main tarsal tunnel release), 64704 with modifier 59 or XS may be supportable — but document the distinct nerve and anatomical separation explicitly. Expect scrutiny.

02Is modifier 50 required for bilateral tarsal tunnel releases?

Yes. 28035 is a unilateral code. Bilateral release requires modifier 50, but payer convention varies — some want one line with modifier 50, others require two lines with LT and RT. Check individual payer rules before submitting.

03What modifier applies when the decision for tarsal tunnel surgery was made at the same E/M visit?

Modifier 57 on the E/M code. Because 28035 carries a 90-day global period, modifier 57 is the correct modifier for a same-day or day-before surgical decision visit — not modifier 25.

04Can 28035 and 28008 (plantar fascia release) be billed together?

Yes, when both procedures are performed and documented. Append modifier 51 to the lower-valued code (typically 28008). Operative note must document separate indications and separate surgical steps for each.

05What ICD-10 codes support 28035?

G57.50 (tarsal tunnel syndrome, unspecified lower limb), G57.51 (right), and G57.52 (left) are the primary diagnosis codes. Non-specific foot pain codes alone are unlikely to clear medical necessity review.

06If the patient returns within the 90-day global for a complication requiring a return to the OR, what modifier applies?

Modifier 78 — unplanned return to the OR for a procedure related to the original surgery during the global period. Modifier 79 is for an unrelated procedure in the global period. Do not invert these.

07Does the site of service affect payment for 28035?

Yes. The HOPD and ASC payments differ significantly — see the Site of Service comparison table on this page. Physician work RVUs are the same in both settings, but practice expense RVUs differ, affecting total facility payment.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

The Mira AI Scribe captures the specific nerve(s) decompressed, flexor retinaculum release details, medial ankle incision approach, and any intraoperative findings such as scar tissue, varicosities, or accessory muscles within the tarsal tunnel — all from dictation. This prevents the most common audit flag on 28035: an operative note that documents the incision but never names the anatomical structures decompressed, which reviewers treat as insufficient to support the code.

See how Mira captures CPT 28035 documentation