Coding and coverage · ICD-10-CM

M45 Ankylosing spondylitis

Not billable (header)Chapter 13

Report one of the more specific codes below.

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Codes under this one

  • M45.0 Ankylosing spondylitis of multiple sites in spine
  • M45.1 Ankylosing spondylitis of occipito-atlanto-axial region
  • M45.2 Ankylosing spondylitis of cervical region
  • M45.3 Ankylosing spondylitis of cervicothoracic region
  • M45.4 Ankylosing spondylitis of thoracic region
  • M45.5 Ankylosing spondylitis of thoracolumbar region
  • M45.6 Ankylosing spondylitis lumbar region
  • M45.7 Ankylosing spondylitis of lumbosacral region
  • M45.8 Ankylosing spondylitis sacral and sacrococcygeal region
  • M45.9 Ankylosing spondylitis of unspecified sites in spine
  • M45.A Non-radiographic axial spondyloarthritisHeader

Instructional notes

Chapter 13

Excludes2Not included here: the patient may have both; report both when both are present.
  • arthropathic psoriasis (L40.5-)
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • compartment syndrome (traumatic) (T79.A-)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Notes
  • Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

This code

Excludes1Not coded here: never report with this code, except when the two conditions are unrelated.
  • arthropathy in Reiter's disease (M02.3-)
  • juvenile (ankylosing) spondylitis (M08.1)
Excludes2Not included here: the patient may have both; report both when both are present.
  • Behçet's disease (M35.2)
Inclusion terms
  • Rheumatoid arthritis of spine

Chapter 13: Diseases of the musculoskeletal system and connective tissue · M40-M54 Dorsopathies (M40-M54)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.