Excision of a deep soft-tissue tumor of the neck measuring less than 5 cm, requiring dissection below the investing fascia to reach the mass.

Verified May 8, 2026 · 5 sources ↓

Medicare: $491.33
Work RVU: 7.47
Global, days: 90
Region: Other

Drawn from CMSAAPC

Documentation requirements

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

Source · Editorial brief grounded in 5 cited references ↓

Tumor size in centimeters (greatest dimension) measured at the time of excision, not from imaging
Explicit statement of depth: subfascial, intramuscular, or deep to investing fascia of the neck
Anatomic location within the neck — level, side, and relationship to surrounding structures (e.g., sternocleidomastoid, carotid sheath)
Operative approach: incision type, planes dissected, and technique used to isolate and excise the mass
Pathology submission documentation confirming specimen sent for histologic evaluation
Preoperative imaging or workup supporting medical necessity and deep location of the lesion

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 52 Reduced services 58 Staged or related 59 Distinct service 62 Co-surgeons 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 5 cited references ↓

CPT 21556 covers removal of a deep neck soft-tissue tumor — one located beneath the superficial fascia, subfascial or intramuscular — where the lesion measures under 5 cm in greatest dimension. The depth requirement is what separates this code from its subcutaneous counterparts (21552/21555): the surgeon must work through or beneath the investing fascia of the neck to reach the mass. Typical targets include deep lipomas, nerve sheath tumors, and other benign or low-grade soft-tissue neoplasms situated within or deep to the cervical musculature.

This code carries a 90-day global period. All routine postoperative visits, wound checks, and suture removals through day 90 are bundled. If you treat a new, unrelated condition during that window, append modifier 24 (E/M) or 79 (procedure). For a complication requiring a return to the OR for a related procedure, use modifier 78 — not 79.

Size and depth are the two axes that drive code selection in this family. If the tumor is 5 cm or larger and deep, step up to 21557. If it turns out to be subcutaneous rather than deep, 21552 (under 5 cm) or 21554 (5 cm or more) applies instead. Document both measurements and the fascial layer relationship explicitly — auditors and payers use operative note language to verify code-level accuracy.

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 (7.47) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (14.71) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	7.47
Practice expense RVU	5.76
Malpractice RVU	1.48
Total RVU	14.71
Medicare national rate	$491.33
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	$491.33
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 21556 get rejected.

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

Tumor size not documented in the operative note — payers default to a lower-level code or deny outright
Depth not specified: notes that omit fascial plane language are frequently downcoded to subcutaneous codes 21552 or 21555
Wrong code selected when lesion is 5 cm or larger — should be 21557; using 21556 for an oversized tumor triggers medical record review
Routine postoperative E/M billed without modifier 24 during the 90-day global period
Unplanned return-to-OR for related complication billed with modifier 79 instead of the correct modifier 78

Frequently asked questions

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

01What distinguishes 21556 from 21552?

Both cover neck soft-tissue tumors under 5 cm, but 21552 is subcutaneous and 21556 is deep — subfascial or intramuscular. The operative note must state the fascial plane crossed to support 21556.

02When should I use 21557 instead of 21556?

Use 21557 when the deep neck tumor measures 5 cm or greater in greatest dimension. Measure at the time of excision; imaging measurements alone are not sufficient.

03Can I bill a same-day E/M with 21556?

Only if it's a significant, separately identifiable service — append modifier 25. Per NCCI policy, E/M work directly related to the decision to excise is bundled into the surgical code.

04How does the 90-day global period affect billing for wound complications?

A return to the OR for a complication related to the excision gets modifier 78. An unrelated procedure in the global window uses modifier 79. An unrelated E/M visit uses modifier 24.

05Is pathology billed separately?

Yes. The surgical pathology code (88302–88309 depending on tissue type and complexity) is billed separately under the technical and professional component structure. It is not bundled into 21556.

06Does site of service affect payment for 21556?

Yes. The HOPD and ASC payment rates differ substantially — see the Site of Service comparison table on this page. Physician work RVUs are the same regardless of setting, but facility payments vary.

07Is 21556 included in MIPS Quality Measure 358 for surgical risk assessment?

Yes. CPT 21556 appears in the denominator of MIPS CQM #358. Adult patients undergoing this procedure should have a documented, data-based preoperative risk assessment and a personal discussion with the surgeon about those risks.

Sources & references

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

Mira Scribe

Mira's AI scribe captures tumor size in centimeters, fascial depth (subfascial, intramuscular, or deep to investing fascia), precise anatomic location within the neck, and the dissection planes documented in dictation. This prevents the two most common downcodes: missing size data that triggers a fallback to 21552, and absent depth language that strips the deep-tissue justification entirely.

See how Mira captures CPT 21556 documentation