Open biopsy of soft tissue in the neck or thorax region for diagnostic tissue sampling

Verified May 8, 2026 · 7 sources ↓

Medicare: $271.88
Work RVU: 2.06
Global, days: 10
Region: Other

Drawn from CMSAAPCNIHFindacodeBillrazor

Documentation requirements

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

Source · Editorial brief grounded in 7 cited references ↓

Specify anatomic location precisely — neck vs. thorax, and laterality (left/right) if applicable
Document tissue type sampled: muscle, fat, fascia, or other connective tissue
Record the indication driving the biopsy (suspected malignancy, infection, inflammatory disease, etc.)
Note surgical approach: open incision with direct tissue excision, not percutaneous needle technique
Document any imaging guidance used and whether it was separately reportable
Pathology order and specimen submission confirmation to support medical necessity

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 59 Distinct service 76 Repeat, same physician 77 Repeat, another physician 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 7 cited references ↓

CPT 21550 covers an open biopsy of soft tissue in the neck or thorax — muscles, fat, fascia, or other connective tissue sampled for pathologic diagnosis. The procedure involves direct incision and excision of a tissue specimen, distinguishing it from needle-based sampling. It sits in the Excision Procedures on the Neck (Soft Tissues) and Thorax section and carries a 10-day global period.

Though the top billing specialties by volume are dermatology, family practice, and internal medicine, orthopedic and surgical oncology teams encounter this code when evaluating soft tissue masses in the neck or chest wall. The site-of-service differential is substantial — HOPD payment dwarfs ASC payment, so facility selection has a real reimbursement impact. See the Site of Service comparison table for current figures.

If imaging guidance is used to direct the biopsy, report the appropriate guidance code separately (e.g., ultrasound or CT guidance) only if the guidance code descriptor does not already include it. Per CMS NCCI policy, radiologic guidance bundled into the primary code descriptor cannot be billed additionally. Verify NCCI PTP edits before appending any guidance code.

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 (2.06) is the surgeon's own effort — the figure physician pay and productivity targets are built on. The total RVU (8.14) adds practice overhead and malpractice, and is what drives the Medicare payment below.

Work RVU	2.06
Practice expense RVU	5.78
Malpractice RVU	0.3
Total RVU	8.14
Medicare national rate	$271.88
Global period	10 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	$271.88
HOPD (APC 5072) Hospital outpatient department	$1,687.37
ASC (PI G2) Ambulatory surgical center (freestanding)	$742.04

Common denial reasons

The recurring reasons claims for CPT 21550 get rejected.

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

Incorrect code selection — percutaneous needle biopsy billed under open biopsy code
Missing or insufficient medical necessity documentation for the tissue sampling
Laterality not specified when payer requires LT/RT modifier for neck procedures
Imaging guidance code denied as bundled when not separately reportable under NCCI
Global period conflict if procedure billed within post-op window of a related prior surgery without modifier 79

Frequently asked questions

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

01What is the global period for CPT 21550?

21550 carries a 10-day global period. Routine follow-up within those 10 days is bundled. Unrelated procedures in that window need modifier 79; related return-to-OR procedures need modifier 78.

02Should I use modifier LT or RT with 21550?

Yes, when the biopsy is performed on one side of the neck or chest, append LT or RT. Some payers require laterality to process the claim; omitting it can trigger a request for additional information or outright denial.

03Can I separately bill imaging guidance when performing a 21550 biopsy?

Only if the guidance code is not already bundled per NCCI. Per CMS NCCI policy, if the primary code descriptor includes radiologic guidance, you cannot bill it separately. Check PTP edits for the specific guidance code before appending.

04What distinguishes 21550 from a needle biopsy of the same area?

21550 is an open procedure — a direct incision with excision of a soft tissue specimen. Percutaneous needle-based sampling uses different codes. Operative notes must explicitly confirm the open approach to support 21550.

05Is modifier 50 appropriate for bilateral neck biopsies billed with 21550?

Modifier 50 applies if biopsies are performed on both sides of the neck or thorax in the same session. Alternatively, some payers prefer two line items with LT and RT. Verify your payer's preference before submitting.

06Why does 21550 show high volume in dermatology and internal medicine when it's a surgical code?

Soft tissue masses of the neck and chest wall are commonly first evaluated and biopsied by non-surgical specialists. Orthopedic and surgical oncology teams tend to handle larger or deeper lesions, but the code is not specialty-restricted.

Sources & references

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

Mira Scribe

Mira's AI scribe captures the anatomic site (neck vs. thorax), tissue type excised, laterality, and the open incision approach from dictation — distinguishing 21550 from percutaneous needle biopsy codes. It also flags whether imaging guidance was used and whether it was directed to the pathology lab. This prevents the most common denial: a coder selecting a needle-biopsy code because the operative note lacked explicit language confirming open excision.

See how Mira captures CPT 21550 documentation