CPT code 86921: Compatibility test, incubation technique2026 Medicare rate & RVUs in California

CMS doesn’t publish an office rate for 86921 in California.

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

What 86921 covers

This serologic crossmatch checks compatibility between a recipient’s serum or plasma and red blood cells from a specific donor unit. The blood bank incubates the sample and donor cells as part of the compatibility assessment before transfusion. Blood bank technologists in hospital transfusion services or reference laboratories typically perform the test, with the laboratory reporting the procedure for each donor unit tested.

Medicare assigns this code physician fee schedule status X, a statutory exclusion because the service is not a physician service under the Medicare statute. When covered, payment is under another applicable fee schedule or payment system, not the physician fee schedule. Status X describes physician fee schedule treatment; it is not itself a coverage determination. Distinguish this method from an immediate-spin, antiglobulin, or electronic compatibility test, which has a separate code.

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 86921 pays more and less in California

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

29 of 29 payment localities

How the 86921 rate is calculated

Each of 86921’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 86921

86921 has no global surgery period, no multiple-procedure, bilateral or assistant-at-surgery adjustment, and no professional/technical split. What changes the payment is where the service happens: the place of service on the claim decides whether Medicare pays the office or the facility rate.

86921 compared with similar codes

How to choose

86920Compatibility testImmediate spin, per unit

Choose 86920 for an immediate-spin crossmatch; choose 86921 when the compatibility test uses incubation.

86922Antiglobulin crossmatchPer donor unit

86922 identifies the antiglobulin technique, while 86921 identifies the incubation technique.

86923Electronic crossmatchPer donor unit

86923 is for an electronic compatibility test; 86921 is for a serologic test using incubation.

Codes related to 86921

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