M45

Non-billable

Ankylosing spondylitis

M45 is the ICD-10-CM code for Ankylosing spondylitis. It is a non-billable category code — use a more specific child code such as M45.0 for billing.

Status
Header (non-billable)
Chapter
M00-M99
Subcodes
11
Edition
FY2026

M00-M99 Diseases of the musculoskeletal system and connective tissue

Includes

  • Rheumatoid arthritis of spine

Excludes1 — not coded here

  • arthropathy in Reiter's disease (M02.3-)
  • juvenile (ankylosing) spondylitis (M08.1)

Excludes2 — not included here

  • Behçet's disease (M35.2)

Frequently asked questions

What is ICD-10 code M45?
M45 is the ICD-10-CM code for "Ankylosing spondylitis". It falls under M00-M99 Diseases of the musculoskeletal system and connective tissue.
Is M45 a billable code?
No — M45 is a non-billable header code. Use a more specific child code (such as M45.0) for billing.
What are the subcodes of M45?
M45 has 11 more specific child codes, including M45.0, M45.1, M45.2.
What is excluded from M45?
Excludes1 (not coded here): arthropathy in Reiter's disease (M02.3-); juvenile (ankylosing) spondylitis (M08.1).

Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.

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