ICD-10 · PDGM grouping
M45 Ankylosing spondylitis
All 20 codes in the M45 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
20
Can lead a claim
18
Cannot lead a claim
2
What CMS assigns to M45
18 of the 20 codes group to Musculoskeletal Rehabilitation; 2 are assigned no clinical group. None of the 20 is assigned a comorbidity subgroup. 18 of the 20 can lead a claim.
Every code in M45
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| M45.0 | Ankylosing spondylitis of multiple sites in spine | Can lead a claim | E | None |
| M45.1 | Ankylosing spondylitis of occipito-atlanto-axial region | Can lead a claim | E | None |
| M45.2 | Ankylosing spondylitis of cervical region | Can lead a claim | E | None |
| M45.3 | Ankylosing spondylitis of cervicothoracic region | Can lead a claim | E | None |
| M45.4 | Ankylosing spondylitis of thoracic region | Can lead a claim | E | None |
| M45.5 | Ankylosing spondylitis of thoracolumbar region | Can lead a claim | E | None |
| M45.6 | Ankylosing spondylitis lumbar region | Can lead a claim | E | None |
| M45.7 | Ankylosing spondylitis of lumbosacral region | Can lead a claim | E | None |
| M45.8 | Ankylosing spondylitis sacral and sacrococcygeal region | Can lead a claim | E | None |
| M45.9 | Ankylosing spondylitis of unspecified sites in spine | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M45.A Non-radiographic axial spondyloarthritis | ||||
| M45.A0 | Non-radiographic axial spondyloarthritis of unspecified sites in spineCMS: Non-radiographic axial spondyloarthritis unsp site in spin | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| M45.A1 | Non-radiographic axial spondyloarthritis of occipito-atlanto-axial regionCMS: Non-radiographic axial spondyloarthritis occipt-atlan-ax rgn | Can lead a claim | E | None |
| M45.A2 | Non-radiographic axial spondyloarthritis of cervical region | Can lead a claim | E | None |
| M45.A3 | Non-radiographic axial spondyloarthritis of cervicothoracic regionCMS: Non-radiographic axial spondyloarthritis of cervicothor rgn | Can lead a claim | E | None |
| M45.A4 | Non-radiographic axial spondyloarthritis of thoracic region | Can lead a claim | E | None |
| M45.A5 | Non-radiographic axial spondyloarthritis of thoracolumbar regionCMS: Non-radiographic axial spondyloarthritis of thrclm region | Can lead a claim | E | None |
| M45.A6 | Non-radiographic axial spondyloarthritis of lumbar region | Can lead a claim | E | None |
| M45.A7 | Non-radiographic axial spondyloarthritis of lumbosacral regionCMS: Non-radiographic axial spondyloarthritis of lumbosacr region | Can lead a claim | E | None |
| M45.A8 | Non-radiographic axial spondyloarthritis of sacral and sacrococcygeal regionCMS: Non-radiographic axial spondyloarthritis sacr/sacrocygl rgn | Can lead a claim | E | None |
| M45.AB | Non-radiographic axial spondyloarthritis of multiple sites in spineCMS: Non-radiographic axial spondyloarthritis mult site in spine | Can lead a claim | E | None |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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