Billing code 21501: Deep abscess drainageMedicare rate & RVUs

Medicare pays $517.71 for 21501 nationally in the office and $327.66 in a hospital or facility. Local office rates run $453.45–$678.40.

Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.

What 21501 covers

A surgeon makes an operative incision to reach and drain a deep collection of pus or blood in the soft tissues of the neck or thorax. Examples include a deep neck-space infection or a deep thoracic soft-tissue collection. The work is distinct from draining a superficial skin abscess and from removing a mass or taking a biopsy. These procedures are commonly performed in a hospital operating room, though the setting depends on the patient and clinical circumstances.

Report 21501 when the documented work is drainage of the deep soft-tissue collection and does not include the additional rib or bone work represented by related codes. The operative report should identify the neck or thoracic site, the depth and nature of the collection, and the drainage performed. This major surgery code has a 90-day global period, including the day-before preoperative visit and related postoperative care. When multiple procedures occur in the same session, the highest-valued is paid in full and others at 50%. Modifier 50 is inappropriate. Medicare does not pay an assistant at surgery for this code; co-surgeons and team surgery are not permitted.

This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.

Where 21501 pays more and less

The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.

109 of 109 payment localities

21501 rates by state

Office rate range in each state. Select a state to see its payment localities.

How the 21501 rate is calculated

Each of 21501’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.

Payment rules and modifiers for 21501

21501 has a 90-day global period: related visits in that window are included in the surgery payment.

What modifiers do to the payment

When to use modifier 51

21501 compared with similar codes

How to choose

21502Deep abscess drainage

21501 covers deep soft-tissue drainage without rib resection. Use 21502 when the operative work includes the rib-related resection described by that code.

21510Thoracic I&D

21510 is for deep thoracic drainage that includes opening bone cortex. 21501 applies when the documented drainage is in soft tissue without that bony work.

21550Soft-tissue biopsy

21550 reports a biopsy of neck or chest tissue for diagnosis. 21501 reports operative drainage of a deep collection, not tissue sampling alone.

Codes related to 21501

Related codes aren’t interchangeable: bill the code that matches the service performed.

Where these rates come from

FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.

CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027

Open CMS sourceHow we calculate rates