M45
Non-billableAnkylosing 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
What this means — in plain language
MedlinePlus · NIHWhat is ankylosing spondylitis? Ankylosing spondylitis (AS) is a type of arthritis of the spine. It causes inflammation (swelling) between your vertebrae (the bones that make up your spine) and the joints between your spine and pelvis. AS inflammation can cause stiffness and make it difficult to move and bend. Symptoms of AS can range from mild to severe back pain. Over time, AS can fuse (grow together) your…
Read more about Ankylosing Spondylitis at MedlinePlus ↗Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.
Includes
- •Rheumatoid arthritis of spine
Excludes1 — not coded here
Excludes2 — not included here
- •Behçet's disease (M35.2)
Frequently asked questions
Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.
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