Surgical · Other

Partial surgical removal of the sternum, excising a discrete portion of the breastbone while leaving the remaining structure intact.

Verified May 8, 2026 · 8 sources ↓

Medicare: $500.35
Total RVUs: 14.98
Global, days: 90
Region: Other

Drawn from CMSAAPCEmednyNIHFastrvu

Documentation requirements

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

Source · Editorial brief grounded in 8 cited references ↓

Operative note must name the specific sternal segment removed (manubrium, sternal body, xiphoid process) and quantify the extent of resection.
Preoperative diagnosis with clinical indication — osteomyelitis, necrosis, lesion, bony prominence, or other — must be explicit in the record.
Document the surgical approach: incision location, length, layers divided, and method of bony resection (rongeur, saw, osteotome).
Pathology submission or intraoperative findings note should confirm the nature of the removed bone when infection or neoplasm is suspected.
If modifier 22 is appended, the operative note must describe the specific factors — adhesions, prior radiation field, anatomic distortion — that increased physician work beyond typical.

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 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 8 cited references ↓

CPT 21620 covers partial ostectomy of the sternum — the surgical removal of a portion of the breastbone. Indications include sternal lesions, osteomyelitis, radiation necrosis, heterotopic ossification, or bony prominences such as an enlarged or symptomatic xiphoid process. The xiphoid process is anatomically part of the sternum, so xiphoidectomy maps to 21620, not an unlisted thorax code.

The code carries a 90-day global period. All routine post-operative visits, wound checks, and dressing changes through day 90 are bundled. Unrelated E/M services billed in that window require modifier 24; a significant, separately identifiable E/M on the day of surgery requires modifier 25. Distinguish 21620 from adjacent codes: 21627 is sternal debridement (soft tissue, no bone removal), and 21630 is radical resection of the entire sternum — a substantially larger oncologic procedure.

The procedure is performed almost exclusively in facility settings (hospital outpatient or inpatient), reflecting the top-billing specialties of cardiac and thoracic surgery. Confirm place of service before submitting; facility vs. non-facility RVU split affects physician payment, and site-of-service mismatches are a common audit trigger.

RVU & reimbursement

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

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	7.1
Practice expense RVU	6.16
Malpractice RVU	1.72
Total RVU	14.98
Medicare national rate	$500.35
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	$500.35
HOPD (APC 5113) Hospital outpatient department	$3,342.87
ASC (PI G2) Ambulatory surgical center (freestanding)	$1,644.87

Common denial reasons

The recurring reasons claims for CPT 21620 get rejected.

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

Unlisted code submitted instead of 21620 for xiphoidectomy — the xiphoid is part of the sternum and 21620 is the correct code.
Place-of-service mismatch between the claim and the actual facility where the procedure was performed.
Medical necessity denial when the operative or clinical record lacks a documented indication (e.g., imaging or culture confirming infection, necrosis, or lesion).
Global period conflict: post-op E/M billed without modifier 24 when the visit falls within the 90-day global window.
Upcoding flag when 21620 is submitted for a procedure that constitutes only sternal debridement (soft tissue), which should be 21627.

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 8 cited references ↓

01Is xiphoidectomy billed as 21620?

Yes. The xiphoid process is part of the sternum. Xiphoidectomy maps to 21620, not an unlisted thorax code. Multiple AAPC forum threads and coding references confirm this. Submit an unlisted code here and expect a denial or downcode.

02What separates 21620 from 21627 and 21630?

21627 is sternal debridement — soft-tissue and surface work without true bone excision. 21620 is partial ostectomy: bone is actually removed. 21630 is radical resection of the full sternum, typically oncologic. Using 21627 when bone was resected leaves significant reimbursement on the table.

03What is the global period for 21620?

90 days. Routine post-op visits, wound checks, and stitch removals through day 90 are bundled. Bill unrelated E/M encounters in that window with modifier 24, or a significant separately identifiable E/M on the day of surgery with modifier 25.

04Can 21620 be billed with modifier 22 for a complex resection?

Yes, when documented. The operative note must specifically describe the factors that increased physician work — prior radiation field, adhesions, infection with extensive involvement, difficult exposure — beyond what is typical for a partial ostectomy. A generic reference to 'difficult case' will not support the modifier.

05Is 21620 typically performed in an ASC or hospital outpatient setting?

The top billing specialties are cardiac and thoracic surgery, and the procedure is almost always performed in a facility setting. HOPD and ASC payment rates differ substantially — see the Site of Service comparison on this page. Confirm place of service before submission; a mismatch is a common audit trigger.

06What related procedure codes should coders check for NCCI bundling when billing 21620?

Use the CMS NCCI PTP lookup tool to check any same-session codes before submitting. Sternal debridement (21627) and wound closure codes are common same-session procedures where bundling edits may apply. Document distinct clinical indications if both services are legitimately separately reportable.

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 specific sternal segment excised (manubrium, body, xiphoid), the extent and method of bony removal, the surgical indication, and the approach description directly from dictation. That prevents the two most common audit flags for 21620: operative notes that omit the anatomic segment (triggering unlisted-code challenges) and records that describe only soft-tissue debridement without confirming bone removal (which auditors recode to 21627).

See how Mira captures CPT 21620 documentation