Is ICD-10-CM code M04 billable?

No, M04 (Autoinflammatory syndromes) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code M04 belong to?

M04 belongs to Chapter 13 of the ICD-10-CM tabular list: M00–M99 (Diseases of the Musculoskeletal System and Connective Tissue).

M04Not billable, use a more specific code below

Autoinflammatory syndromes

chapter 13: Diseases of the Musculoskeletal System and Connective Tissue

5 billable codes under M04: none are a CC or MCC; 4 map to HCC 94 (Systemic Lupus Erythematosus and Other Specified Systemic Connective Tissue Disorders).An HCC counts toward a Medicare Advantage patient's risk score.

Instructional notes

Excludes2: not included here, code separately if applicable

Crohn's disease (K50.-)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Covers site and laterality, acute injury versus chronic musculoskeletal conditions, 7th characters for pathologic fractures, osteoporosis with or without current fracture, and multisystem inflammatory syndrome.

Site and laterality (page 60)
Acute traumatic versus chronic or recurrent musculoskeletal conditions (page 61)
Coding of Pathologic Fractures (page 61)
Osteoporosis (page 61)
Multisystem Inflammatory Syndrome (page 62)

Read Section I.C.13 (page 60)

All codes under M04

M04 can't be used on a claim. Pick a billable code below; grey headings group them.

M04 MS-DRGs

As the principal diagnosis, all 5 billable codes under M04 group to MS-DRG 545, 546, or 547 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

Other codes that refer to M04

Notes on these codes point to M04.

E85.0 Code Also: autoinflammatory syndromes (M04.-)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

Autoimmune Diseases

Your immune system protects you from disease and infection by attacking germs that get into your body, such as viruses and bacteria. Your immune system can tell that the germs aren't part of you, so it destroys them. If you have an autoimmune disease, your immune system attacks the healthy cells of your organs and tissues by mistake.

Code history

Added in FY2017 (effective October 1, 2016). No changes since.