Open biopsy of deep soft tissue in the forearm, involving surgical exposure to obtain a tissue sample for pathological analysis.

Verified May 8, 2026 · 5 sources ↓

Medicare: $358.39
Work RVU: 4.16
Global, days: 90
Region: Wrist

Drawn from CMSAAOSFindacode

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Depth of dissection documented — specify superficial vs. subfascial tissue layer sampled
Laterality clearly stated (right forearm, left forearm, or bilateral) in the operative note
Indication for biopsy with supporting diagnosis or clinical finding driving the procedure
Pathology requisition and specimen labeling consistent with the operative note
Operative note identifies the incision approach and anatomic location within the forearm
Wound closure technique documented to support depth and complexity of the procedure

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 76 Repeat, same physician 77 Repeat, another physician 78 Unplanned return — related 79 Unrelated during global LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 5 cited references ↓

CPT 25066 covers an open biopsy of deep soft tissue of the forearm. This is a subcutaneous or subfascial tissue sampling requiring surgical incision and exposure — not a needle or superficial punch biopsy. The specimen goes to pathology, and the operative note must clearly document the depth of dissection and tissue layer sampled.

The code carries a 90-day global period, which means all routine follow-up through day 90 is bundled into the payment. If the biopsy leads to a definitive resection or separate procedure within that window, use modifier 58 (staged or related procedure) or 78 (unplanned return for a related procedure). An E&M visit on the day of service to decide whether to proceed with surgery is separately billable with modifier 57.

This code is used across orthopedic surgery, hand surgery, and plastic and reconstructive surgery. Laterality modifiers LT and RT are essential — claims missing these on a unilateral procedure are a common payer rejection trigger. When both forearms are biopsied in the same session, append modifier 50 and bill once.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU vs. total RVU

The work RVU (4.16) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (10.73) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	4.16
Practice expense RVU	5.75
Malpractice RVU	0.82
Total RVU	10.73
Medicare national rate	$358.39
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	$358.39
HOPD (APC 5073) Hospital outpatient department	$2,967.63
ASC (PI A2) Ambulatory surgical center (freestanding)	$1,248.36

Common denial reasons

The recurring reasons claims for CPT 25066 get rejected.

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

Missing laterality modifier — payers reject claims for extremity procedures without LT or RT
Bundling conflict when billed same-day with a more extensive forearm procedure that includes biopsy as an integral step
Modifier 59 absent when 25066 is billed alongside another forearm or wrist code on the same date of service
Insufficient documentation of tissue depth — claims flagged when operative note doesn't distinguish deep from superficial biopsy
E&M billed same-day without modifier 25 or 57, triggering automatic denial under global surgery rules

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01What's the difference between CPT 25065 and 25066?

25065 is the superficial soft tissue biopsy of the forearm; 25066 is the deep (subfascial) biopsy. The distinction hinges on the layer of tissue sampled and must be explicitly documented in the operative note. Billing 25066 without documentation of deep dissection is an audit target.

02Do I need modifier LT or RT on every claim for 25066?

Yes. Forearm procedures are paired-extremity services. Most payers — including Medicare — expect laterality on all claims for upper extremity codes. Missing LT or RT is one of the most common clean-claim failures for this code.

03Can I bill an E&M on the same day as 25066?

Yes, under two scenarios. If the visit was the decision point for performing the biopsy, append modifier 57 to the E&M. If the E&M addressed a separate, unrelated problem, append modifier 25. Without one of these modifiers, the E&M will deny under the 90-day global package rules.

04If pathology confirms a malignancy and resection is performed within the 90-day global, how do I bill the resection?

Bill the resection with modifier 58 — it signals a staged or therapeutically related procedure planned after the biopsy. Do not use modifier 79 (unrelated procedure) for this scenario; that modifier is for genuinely unrelated procedures during the postoperative period.

05Can 25066 be billed bilaterally?

Yes. When biopsies are performed on both forearms in the same session, bill 25066 once with modifier 50. Some payers want two line items with LT and RT instead — check payer-specific instructions before submitting.

06What ICD-10 diagnoses most commonly support 25066?

Common supporting diagnoses include soft tissue neoplasm of the forearm (benign or uncertain behavior), soft tissue mass, lipoma, or lesions suspicious for malignancy. The diagnosis code must align with the clinical indication documented in the pre-op note and pathology order.

Sources & references

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

Mira Scribe

Mira's AI scribe captures tissue depth, anatomic forearm location, laterality, and approach from dictation, then flags the note if depth of dissection isn't explicitly documented. That prevents the most common audit failure for 25066 — operative notes that describe only 'biopsy of forearm mass' without confirming subfascial involvement to justify the deep soft tissue code.

See how Mira captures CPT 25066 documentation