HCPCS Level II · Medical services and quality measures
M1311Anaphylaxis due to the vaccine on or before the date of the encounter
✓ Active
Source: CMS HCPCS quarterly update, October 2026. Page updated September 29, 2026.
About M1311
M1311 is an HCPCS Level II code in the M series (medical services and quality measures), describing anaphylaxis due to the vaccine on or before the date of the encounter.
It was added to HCPCS effective 01/01/2024.
Its Medicare coverage code is "C", meaning coverage is left to the Medicare contractor's judgment.
Details
- Short description
- Aphlx to vax bef enc
- Date added
- 01/01/2024
- Action effective
- 01/01/2024
- BETOS
- Z2
Related M13xx codes
- M1300Influenza immunization was not administered for reasons documented by clinician (e.g., patient allergy or other medical reasons, patient declined or other patient reasons, vaccine not available or other system reasons)
- M1301Patient identified as a tobacco user received tobacco cessation intervention during the measurement period or in the six months prior to the measurement period (counseling and/or pharmacotherapy)
- M1302Screening, diagnostic, film digital or digital breast tomosynthesis (3d) mammography results documented and reviewed
- M1303Hospice services provided to patient any time during the measurement period
- M1304Patient did not receive any pneumococcal conjugate or polysaccharide vaccine on or after their 19th birthday and before the end of the measurement period
- M1305Patient received any pneumococcal conjugate or polysaccharide vaccine on or after their 19th birthday and before the end of the measurement period
- M1306Patient had anaphylaxis due to the pneumococcal vaccine any time during or before the measurement period
- M1307Documentation stating the patient has received or is currently receiving palliative or hospice care
- M1308Influenza immunization was not administered, reason not given
- M1309Palliative care services provided to patient any time during the measurement period
- M1310Patient screened for tobacco use and received tobacco cessation intervention during the measurement period or in the six months prior to the measurement period (counseling, pharmacotherapy, or both), if identified as a tobacco user
- M1312Patient not screened for tobacco use
Common questions about M1311
Is HCPCS M1311 still valid?
- Yes. M1311 is active in the CMS October 2026 HCPCS file.
Does Medicare cover M1311?
- Its coverage code is "C": coverage is left to the Medicare contractor's judgment. Check the local coverage determination for your region.