ICD-10-CM 2027 diagnosis code

M04Autoinflammatory syndromes

Not billable — use a more specific code

M04 is a header code, so it can't be reported by itself. Choose one of the 5 more specific codes beneath it.

Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS, effective October 1, 2026. Updated September 29, 2026. About our data

About M04

M04 is the ICD-10-CM diagnosis code for autoinflammatory syndromes. It belongs to block M04 (autoinflammatory syndromes) and chapter 13 (diseases of the musculoskeletal system and connective tissue). It is a header code, so it can't be reported by itself; one of its 5 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: M04.1 (syndromes), M04.2 (syndromes), M04.3 (syndrome), M04.8 (syndromes) and M04.9 (unspecified).

The conditions in its Excludes2 note aren't part of M04, but may be coded alongside it if the patient has both: Crohn's disease (K50.-).

It was added in FY2017, effective October 1, 2016.

Specific codes under M04

Coding notes

Excludes2Not included here — may be reported together if both conditions exist

Crohn's disease (K50.-)

Notes that apply from higher levels

Instructions written at a parent level also apply to M04.

Broader instructions also apply from Chapter 13: Diseases of the musculoskeletal system and connective tissue.

Codes whose notes reference M04

E85.0Code also

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2017 (effective 10/1/2016): Added
No changes since FY2017.

Common questions about M04

Is M04 billable?: No. M04 is a header code. Report one of its more specific subcodes instead.