Excision of a subcutaneous soft tissue tumor in the thigh or knee area measuring 3 cm or greater.

Verified May 8, 2026 · 7 sources ↓

Medicare: $408.16
Work RVU: 5.76
Global, days: 90
Region: Knee

Drawn from CMSAAPCFindacodeBedrockbillingNIH

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Lesion size documented in centimeters — must confirm 3 cm or greater to support 27337 over 27327
Depth of lesion relative to fascia: confirm subcutaneous (above deep fascia) to distinguish from subfascial codes 27339/27364
Anatomic location specified as thigh or knee area with laterality (left vs. right)
Operative note describes excision technique, wound closure method, and any complicating factors
Pathology specimen submitted and report documented; diagnosis code should align with final pathology when available
Pre-operative imaging or clinical assessment supporting medical necessity for excision

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 25 Significant separate E/M 50 Bilateral procedure 51 Multiple procedures 58 Staged or related 59 Distinct service 76 Repeat, same physician 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant LT Left side RT Right side XS Separate structure

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 27337 covers open excision of a subcutaneous soft tissue mass — lipoma, ganglion, or similar benign or malignant lesion — located in the thigh or knee region, where the lesion measures 3 cm or greater. The size threshold is the key differentiator from 27327, which covers the same anatomic region for lesions under 3 cm. Depth matters too: subcutaneous means the mass is above the deep fascia. If the lesion is subfascial or intramuscular, step up to 27339 (subfascial, under 5 cm) or 27364 (subfascial/intramuscular, 5 cm or greater).

The 90-day global period applies. All routine post-op care through day 90 is bundled. An E/M visit on the same day as the excision requires modifier 25 if it was a separate, identifiable service — for example, evaluating an unrelated complaint. Pathology (88302–88309) is separately reportable and not bundled into 27337. If the excised specimen goes to pathology, bill the appropriate level; do not assume it is included.

Site-of-service matters for reimbursement. The HOPD rate is substantially higher than the ASC rate (see the Site of Service comparison table on this page). For bilateral same-session excisions on both limbs, append modifier 50. Use LT or RT when only one side is treated and your payer requires laterality. Modifier 22 applies when operative complexity — unusually large specimen, difficult dissection, extensive reconstruction — is documented in the operative note.

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 (5.76) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (12.22) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	5.76
Practice expense RVU	5.07
Malpractice RVU	1.39
Total RVU	12.22
Medicare national rate	$408.16
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	$408.16
HOPD (APC 5073) Hospital outpatient department	$2,967.63
ASC (PI G2) Ambulatory surgical center (freestanding)	$1,248.36

Common denial reasons

The recurring reasons claims for CPT 27337 get rejected.

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

Size not documented: payer downcodes to 27327 when the operative note lacks a measured lesion size of 3 cm or greater
Depth mismatch: billing 27337 (subcutaneous) when operative note describes subfascial or intramuscular dissection — should be 27339 or 27364
Unbundling local anesthesia administration separately; local anesthesia is integral to the excision and not separately billable
E/M billed same-day without modifier 25, triggering NCCI bundle denial when the visit was part of the surgical decision
Diagnosis code does not support medical necessity — unspecified or benign-appearing lesions without documented clinical indication for excision

Frequently asked questions

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

01What separates 27337 from 27327?

Size only. Both codes cover subcutaneous soft tissue excision in the thigh or knee area. 27327 is for lesions under 3 cm; 27337 is for lesions 3 cm or greater. If the operative note doesn't state a measurement, expect a downcode to 27327.

02When should I use 27339 or 27364 instead of 27337?

When the mass is subfascial or intramuscular rather than subcutaneous. 27339 covers subfascial lesions under 5 cm in the thigh/knee; 27364 covers subfascial or intramuscular lesions 5 cm or greater. Depth documentation in the operative note drives the code selection.

03Is pathology bundled into 27337?

No. Pathology codes 88302–88309 are separately reportable. Bill the appropriate level based on the complexity of the pathologic examination. Confirm the specimen was submitted and document the pathology report in the record.

04Can I bill an E/M on the same day as a 27337 excision?

Yes, but only if it was a significant and separately identifiable service unrelated to the surgical decision. Append modifier 25 to the E/M. The visit and procedure do not require different diagnoses, but the note must support a distinct clinical evaluation beyond the pre-surgical assessment.

05How do I bill if excisions are performed on both the left and right thigh or knee at the same session?

Report 27337 with modifier 50 for a bilateral procedure on the same claim line. Some payers prefer two lines with LT and RT instead — check your payer's billing guidelines. Do not report two units without confirming payer preference.

06What modifier applies if the patient has to return to the OR within the 90-day global for a related complication?

Modifier 78. Use it for an unplanned return to the operating room for a procedure related to the original excision — for example, hematoma evacuation or wound dehiscence repair. Modifier 79 is for unrelated procedures during the global period; do not use these interchangeably.

07Does the 90-day global period affect post-op office visits?

Yes. Routine post-op visits tied to recovery from the 27337 excision are bundled through day 90. If a visit addresses a problem unrelated to the excision, bill the E/M with modifier 24 to bypass the global period edit.

Sources & references

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

Mira Scribe

Mira's AI scribe captures lesion size in centimeters, depth relative to the fascia, anatomic location, laterality, and excision technique from dictation — the four variables that determine whether 27337 is defensible or will be downcoded. It flags operative notes that omit a numeric size measurement or describe the dissection as subfascial, prompting the surgeon to clarify before the note is finalized. That prevents the two most common denial patterns for this code: size-based downcoding to 27327 and depth-based downcoding to 27339.

See how Mira captures CPT 27337 documentation