Ankylosing spondylitis (M45)
ICD-10 code M45 covers ankylosing spondylitis, a chronic inflammatory condition affecting the spine. These codes specify which parts of the spine are involved, from multiple spinal sites to precise regions like cervical, thoracic, lumbar, and sacral. There are also codes for non-radiographic axial spondyloarthritis, a related condition without visible spine changes on X-rays.
The ICD-10 code for ankylosing spondylitis (M45) helps identify the extent and location of inflammation along the spine. Subcodes such as M45.2 correspond to ankylosing spondylitis of the cervical region, which may be called rheumatoid arthritis of cervical spine or cervical arthritis by some clinicians. Codes like M45.4 refer to thoracic spinal involvement, sometimes described as chest deformity due to ankylosing spondylitis. The code M45.9 accounts for unspecified spinal sites and covers cases with additional organ involvement or multisystem symptoms. Additionally, the M45.A series covers non-radiographic axial spondyloarthritis, a related condition where standard imaging does not show spine damage but symptoms resemble ankylosing spondylitis. These distinctions support accurate diagnosis, treatment planning, and medical billing focused on specific spine areas affected by inflammatory spondyloarthropathies.
Diseases of the musculoskeletal system and connective tissue (M00–M99)
Spondylopathies (M45-M49)
M45 Ankylosing spondylitis
- 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 spondyloarthritis
- M45.A0 Non-radiographic axial spondyloarthritis of unspecified sites in spine
- M45.A1 Non-radiographic axial spondyloarthritis of occipito-atlanto-axial region
- M45.A2 Non-radiographic axial spondyloarthritis of cervical region
- M45.A3 Non-radiographic axial spondyloarthritis of cervicothoracic region
- M45.A4 Non-radiographic axial spondyloarthritis of thoracic region
- M45.A5 Non-radiographic axial spondyloarthritis of thoracolumbar region
- M45.A6 Non-radiographic axial spondyloarthritis of lumbar region
- M45.A7 Non-radiographic axial spondyloarthritis of lumbosacral region
- M45.A8 Non-radiographic axial spondyloarthritis of sacral and sacrococcygeal region
- M45.AB Non-radiographic axial spondyloarthritis of multiple sites in spine
Ankylosing spondylitis (M45)
Instructional Notations
Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
- Rheumatoid arthritis of spine
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
- Behçet's disease M35.2
