Open decompression of the median nerve at the wrist, including transverse carpal ligament release and any neuroplasty or nerve transposition performed through an open incision.

Verified May 8, 2026 · 9 sources ↓

Medicare: $482.64
Total RVUs: 14.45
Global, days: 90
Region: Wrist

Drawn from CMSKzanowAAPCAffinitycoreMedicare.gov

Documentation requirements

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

Source · Editorial brief grounded in 9 cited references ↓

Confirm open approach — document that no endoscope was used and describe the incision site and length
Specify laterality (right, left, or bilateral) in the operative note and on the claim
Record pre-operative electrodiagnostic or imaging studies confirming median nerve compression at the carpal tunnel
If 64719 is billed alongside 64721, document pre-operative diagnostic studies confirming ulnar nerve pathology at Guyon's canal in both the pre-op diagnosis and indications paragraph
If 64727 is added, confirm use of the operating microscope for internal neurolysis and document accordingly
Note any nerve transposition performed — bundled into 64721 but relevant for audit defense

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 50 Bilateral procedure 51 Multiple procedures 52 Reduced services 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 9 cited references ↓

CPT 64721 covers open carpal tunnel release — division of the transverse carpal ligament to decompress the median nerve at the wrist, with or without neuroplasty or nerve transposition. The open approach is distinct from the endoscopic technique (29848): per NCCI policy, 64721 subsumes 29848 when both are performed on the same wrist at the same encounter, and if an endoscopic attempt is converted to open, only 64721 is reportable. If internal neurolysis is performed under an operating microscope during the same session, add-on code 64727 may be reported alongside 64721.

The code carries a 90-day global period. All routine follow-up through day 90 — wound checks, suture removal, dressing changes — is bundled. Anything unrelated to the carpal tunnel release billed during that window requires modifier 24 (E/M) or modifier 79 (unrelated procedure). Ulnar nerve decompression at Guyon's canal (64719) is bundled into 64721 by NCCI; to unbundle, you need documented pre-operative diagnostic studies confirming ulnar nerve pathology listed in both the pre-op diagnosis and the indications paragraph — then append modifier 59. There is no NCCI bundle between 64721 and open ulnar nerve surgery at the elbow (64718); use modifier 51 on the lesser-valued code.

64721 is unilateral. For bilateral same-session procedures, append modifier 50 to a single line or report on two lines with RT and LT — payer preference varies, so confirm before submitting. When a same-day procedure such as trigger finger release (26055) is performed and NCCI does not bundle it with 64721, append modifier 51 to the secondary code.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	4.85
Practice expense RVU	8.61
Malpractice RVU	0.99
Total RVU	14.45
Medicare national rate	$482.64
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	$482.64
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 64721 get rejected.

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

29848 billed same-day same-wrist as 64721 — NCCI bundles the endoscopic code into the open code with no modifier override
64719 billed without documentation of pre-operative diagnostic studies confirming ulnar nerve pathology, triggering NCCI bundle denial
Bilateral procedure submitted without modifier 50 or RT/LT, resulting in edit or duplicate-service denial
Routine post-op visits billed within the 90-day global period without modifier 24 or 79
Missing or insufficient pre-operative electrodiagnostic documentation supporting medical necessity under payer LCD

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 9 cited references ↓

01Can 29848 and 64721 ever be billed together on the same wrist?

No. NCCI policy explicitly states that 64721 includes the procedure described by 29848 when performed on the same wrist at the same encounter. If the endoscopic approach was attempted and converted to open, report only 64721 — modifier 22 may apply if the conversion significantly increased operative complexity.

02How do you bill bilateral carpal tunnel release performed in the same session?

64721 is a unilateral code. For bilateral same-session release, either append modifier 50 to one line or report 64721 on two lines with RT on one and LT on the other. Payer preference varies — check individual carrier guidelines before submitting, as some commercial payers reject modifier 50 and require RT/LT.

03Can 64719 be billed with 64721 if the surgeon also decompressed the ulnar nerve at Guyon's canal?

Yes, but only with supporting documentation. An NCCI edit bundles 64719 into 64721. To override it with modifier 59, you need pre-operative diagnostic studies confirming ulnar nerve pathology documented in both the pre-op diagnosis and the indications for surgery paragraph. Without that documentation, 64719 will deny.

04What modifier applies when the surgeon performs trigger finger release (26055) the same day as 64721?

NCCI does not bundle 26055 with 64721. Append modifier 51 to 26055 as the secondary procedure. Expect the payer to reduce payment on 26055 — Medicare pays the second through fifth procedures at 50 percent of the fee schedule amount.

05Does the 90-day global period affect billing for an E/M visit during post-op recovery?

Yes. Any E/M visit within the 90-day global period that is related to the carpal tunnel release is bundled — bill nothing. For an unrelated condition (e.g., a new injury or unrelated diagnosis), append modifier 24 to the E/M code and document that the visit was unrelated to the surgical procedure.

06When is modifier 22 appropriate for 64721?

Append modifier 22 when the procedure is substantially more complex than typical — for example, a failed endoscopic conversion requiring significantly extended dissection, or revision surgery in a previously scarred field. Document the specific factors increasing complexity; without that narrative, modifier 22 claims are routinely denied or ignored.

Sources & references

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

Mira AI Scribe

Mira's AI scribe captures the open approach confirmation, incision details, laterality, transverse carpal ligament division, and any nerve transposition or internal neurolysis from dictation — differentiating 64721 from a billable 64727 add-on when an operating microscope is used. It also flags whether ulnar symptoms were addressed, prompting documentation of pre-operative nerve studies before 64719 is added. This prevents the two most common NCCI-driven denials: unbundled 29848 and unsupported 64719.

See how Mira captures CPT 64721 documentation