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0021U

What 0021U is

This code appears in the Medicare NCCI edit tables. It has no RVUs in the CY2026 Physician Fee Schedule file.

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Medically Unlikely Edit (MUE)

Medicare caps 0021U at 1 unit per date of service for practitioner claims (MAI 2 - date of service edit (absolute): units above the MUE never pay), rationale: Code Descriptor / CPT Instruction. Units above the cap are denied unless the edit's adjudication rules allow an appeal with documentation.

Billed with 0021U? These codes are bundled into it

0021U is a Column 1 code in 20 active NCCI PTP edits. When one of these Column 2 codes is reported on the same date of service, it is denied as bundled - unless the edit's modifier indicator is 1 and documentation supports a distinct service with an NCCI-associated modifier.

Column 2 codeShort descriptionModifier indicator
0251U1 - modifier may bypassCheck pair
0512U0 - no modifier bypassCheck pair
0513U0 - no modifier bypassCheck pair
80503Path clin consltj sf 5-201 - modifier may bypassCheck pair
80504Path clin consltj mod 21-401 - modifier may bypassCheck pair
80505Path clin consltj high 41-601 - modifier may bypassCheck pair
80506Path clin consltj prolng svc1 - modifier may bypassCheck pair
83516Immunoassay nonantibody1 - modifier may bypassCheck pair
83518Immunoassay dipstick1 - modifier may bypassCheck pair
83519Ria nonantibody1 - modifier may bypassCheck pair
83520Immunoassay quant nos nonab1 - modifier may bypassCheck pair
86294Immunoassay tumor qual1 - modifier may bypassCheck pair
86316Immunoassay tumor other1 - modifier may bypassCheck pair
88182Cell marker study1 - modifier may bypassCheck pair
88184Flowcytometry/ tc 1 marker1 - modifier may bypassCheck pair
88185Flowcytometry/tc add-on1 - modifier may bypassCheck pair
88187Flowcytometry/read 2-81 - modifier may bypassCheck pair
88188Flowcytometry/read 9-151 - modifier may bypassCheck pair
88189Flowcytometry/read 16 & >1 - modifier may bypassCheck pair
96523Irrig drug delivery device0 - no modifier bypassCheck pair

0021U is bundled into these codes

0021U appears as a Column 2 code in 25 active edits. Reported with one of these Column 1 codes on the same date of service, 0021U is the code that denies.

Column 1 codeShort descriptionModifier indicator
0005U0Check pair
0011M0Check pair
0012M0Check pair
0013M0Check pair
0016M0Check pair
0047U0Check pair
0113U0Check pair
0133U0Check pair
0228U0Check pair
0317U0Check pair
0339U0Check pair
0343U0Check pair
0359U1Check pair
0363U0Check pair
0403U0Check pair

Data: CMS CY2026 Physician Fee Schedule RVU file (October release, RVU26D) and Medicare NCCI PTP practitioner edits v32.3 (2026 Q4). Verify against the official files before billing or contracting decisions.