M1311 — Anaphylaxis due to the vaccine on or before the date of the encounter
M1311 is a HCPCS Level II code for anaphylaxis due to the vaccine on or before the date of the encounter. It belongs to the Medical Services section. Whether Medicare pays it depends on the coverage rule below.
Medicare coverage: Carrier judgment
Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.
From the coverage field of the CMS Alpha-Numeric HCPCS File, release 2026Q3-Jul. This states Medicare’s position on the code, not on your particular claim.
Physician fee schedule statusM
Measurement code. Used for reporting purposes only; never paid.
Global period: XXX
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The CMS record for M1311
- Long descriptor
- Anaphylaxis due to the vaccine on or before the date of the encounter
- Short descriptor
- Aphlx to vax bef enc
- Added
- January 1, 2024
- BETOS
- Z2
- Pricing indicator
- 00 — Not priced by Part B
The official wording. This is what the code means.
CMS's 28-character form, which is what shows up on a remittance advice.
When CMS introduced the code.
Berenson-Eggers Type of Service — CMS's own analytic grouping.
Service not separately priced by Part B — not covered, bundled into another service, or used by Part A only.
Codes adjacent to M1311
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If M1311 is not quite right, the correct code is very often within a few positions of it.
- 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
- M1313Tobacco screening not performed or tobacco cessation intervention not provided during the measurement period or in the six months prior to the measurement period
- M1314Bmi not documented and no reason is given
- M1315Colorectal cancer screening results were not documented and reviewed; reason not otherwise specified
- M1316Current tobacco non-user
- M1317Patients who are counseled on connection with a csp and explicitly opt out
- M1318Patients who did not have documented contact with a csp for at least one of their screened positive hrsns within 60 days after screening or documentation that there was no contact with a csp
- M1319Patients who had documented contact with a csp for at least one of their screened positive hrsns within 60 days after screening
Questions about M1311
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. It sits in the Medical Services section.
Does Medicare cover M1311?
The CMS HCPCS file marks M1311 as "Carrier judgment". Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.
How is M1311 paid under the physician fee schedule?
M1311 carries PFS status code M. Measurement code. Used for reporting purposes only; never paid.