Radical resection of a malignant soft tissue tumor (such as a sarcoma) of the neck or anterior thorax measuring 5 cm or greater, including resection of surrounding tissue and any involved anatomic structures.

Verified May 8, 2026 · 7 sources ↓

Medicare: $1,221.47
Total RVUs: 36.57
Global, days: 90
Region: Other

Drawn from CMSNIHAAPCCgsmedicare

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Tumor size documented as 5 cm or greater, inclusive of required surgical margins — not just the gross specimen diameter
Operative note must name the specific anatomical structures resected or assessed for involvement beyond the tumor capsule
Pathology report confirming malignant histology (e.g., sarcoma) linked to the resected specimen
Clearly documented surgical approach and extent of resection distinguishing radical resection from simple excision
If neck dissection (38724) performed concurrently, operative note must support it as a distinct procedure with separate surgical work described
Preoperative imaging or biopsy results establishing tumor location within the neck or anterior thorax soft tissues

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 51 Multiple procedures 52 Reduced services 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 21558 describes a radical resection — not a simple excision — of a soft tissue malignant tumor arising from the neck or anterior thorax when the tumor plus required margins measures 5 cm or greater. The resection extends beyond the tumor boundaries to encompass surrounding tissue and any adjacent anatomical structures suspected of involvement. This is the larger-tumor companion to 21557, which covers the same procedure for tumors under 5 cm. The size threshold is the tumor-plus-margin measurement, not the tumor alone.

The 90-day global period applies. Any staged or unplanned return to the OR for a related complication bills with modifier 78; an unrelated procedure in the global window requires modifier 79. Same-day wound debridement (97597) is bundled by NCCI — it is considered a component of the resection and cannot be billed separately on the date of surgery. If a modified radical neck dissection (38724) is performed at the same encounter, confirm whether it is integral to the resection or a separately reportable procedure; payer policies vary and supporting documentation must clearly establish distinct surgical work.

Otolaryngology is the dominant billing specialty for this code. When orthopedic or surgical oncology teams bill it, payers occasionally query specialty mismatch — ensure the operative note and ICD-10 diagnosis coding (typically a soft tissue sarcoma category) support the clinical picture. Pathology confirmation of malignancy in the operative or post-op documentation is expected and is routinely requested on audit.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	21.04
Practice expense RVU	11.03
Malpractice RVU	4.5
Total RVU	36.57
Medicare national rate	$1,221.47
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	$1,221.47
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 21558 get rejected.

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

Tumor size not documented as 5 cm or greater — payer downcodes to 21557 without explicit margin-inclusive measurement in the operative note
Same-day 97597 wound debridement billed alongside 21558 — NCCI bundles this; 97597 denies without modifier override where not applicable
Missing or delayed pathology report at time of billing — payers treating malignancy designation as unsubstantiated without histologic confirmation
Specialty mismatch flag when non-ENT/surgical oncology providers bill the code without clinical narrative supporting soft tissue tumor of neck or anterior thorax
ICD-10 diagnosis code does not map to a soft tissue malignancy of the neck or anterior thorax, triggering medical necessity denial

Frequently asked questions

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

01What distinguishes 21558 from 21557?

Tumor-plus-margin size. 21557 covers radical resection of neck or anterior thorax soft tissue tumors under 5 cm; 21558 is for 5 cm or greater. Use the margin-inclusive measurement from the operative or pathology report, not the gross tumor diameter alone.

02Can 38724 (modified radical neck dissection) be billed with 21558?

Potentially yes, but it is contested. Some payers treat neck dissection as integral to a radical neck tumor resection. If the dissection represents distinct surgical work at a separate anatomic level, document it clearly and expect scrutiny. Check NCCI PTP edits via the CGS Medicare lookup tool before billing both codes together.

03Is 97597 wound debridement billable on the same day as 21558?

No. NCCI bundles 97597 as a component of the resection procedure for the 21552–21558 code family. Billing 97597 on the date of surgery will deny.

04What ICD-10 codes should accompany 21558?

Malignant soft tissue neoplasm codes from the C49.0 category (malignant neoplasm of connective and soft tissue of head, face, and neck) are the standard pairing. Confirm the specific subsite. Using benign neoplasm or unspecified codes will generate a medical necessity denial.

05How does the 90-day global period affect post-op billing?

All routine post-op visits, wound checks, and dressing changes through day 90 are bundled. If you need to bill an E/M for an unrelated condition during the global window, append modifier 24. A return to the OR for a related complication bills with modifier 78; an unrelated return-to-OR procedure uses modifier 79.

06Does site of service affect payment for 21558?

Yes. HOPD and ASC reimbursement differ — see the Site of Service comparison on this page. The physician's professional fee is also subject to site-of-service differential under the CMS Physician Fee Schedule 2026.

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 tumor's location (neck versus anterior thorax), the margin-inclusive size measurement, the extent of resection into surrounding structures, and histologic designation from preoperative biopsy. It flags when the operative dictation omits the 5 cm threshold or describes the procedure as a 'simple excision,' both of which trigger downcoding to 21557 or an integumentary excision code on audit.

See how Mira captures CPT 21558 documentation