M1311 – Anaphylaxis due to the vaccine on or before the date of the encounter

HCPCS Level II code · M codes: Medical Services and Quality Measures

Active code Carrier judgment

HCPCS codeM1311
Long description
Anaphylaxis due to the vaccine on or before the date of the encounter
Short description
Aphlx to vax bef enc
Pricing indicator
00 Not separately priced by Part B (bundled, not covered or Part A only)
Medicare coverage
C Carrier judgment – coverage decided by the Medicare contractor
BETOS category
Z2 Undefined codes
Added
January 1, 2024
Last change
January 1, 2024 – No change

Frequently asked questions

What is HCPCS code M1311?

M1311 is a HCPCS Level II code for anaphylaxis due to the vaccine on or before the date of the encounter.

Does Medicare cover M1311?

The HCPCS file lists coverage code C: Carrier judgment – coverage decided by the Medicare contractor. Coverage and payment also depend on local coverage determinations and the patient’s plan.

Nearby M codes

Source: CMS HCPCS Level II quarterly file, October 2026. Reference only – check payer policy before billing.