C9791

What C9791 is

Magnetic resonance imaging with inhaled hyperpolarized xenon-129 contrast agent, chest, including preparation and administration of agent

HCPCS Level II long description, CMS October 2026 file. See the C codes page for the full section.

Medically Unlikely Edit (MUE)

Medicare caps C9791 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 C9791? These codes are bundled into it

C9791 is a Column 1 code in 1 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.

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.