| M438X2 | Other specified deforming dorsopathies, cervical region |
| M438X3 | Other specified deforming dorsopathies, cervicothoracic region |
| M438X4 | Other specified deforming dorsopathies, thoracic region |
| M438X5 | Other specified deforming dorsopathies, thoracolumbar region Other specified deforming dorsopathies, thoracolumbar region |
| M438X6 | Other specified deforming dorsopathies, lumbar region |
| M438X7 | Other specified deforming dorsopathies, lumbosacral region |
| M438X8 | Oth deforming dorsopathies, sacral and sacrococcygeal region Other specified deforming dorsopathies, sacral and sacrococcygeal region |
| M438X9 | Other specified deforming dorsopathies, site unspecified |
| M439 | Deforming dorsopathy, unspecified |
| M45 | Ankylosing spondylitis |
| M450 | Ankylosing spondylitis of multiple sites in spine |
| M451 | Ankylosing spondylitis of occipito-atlanto-axial region |
| M452 | Ankylosing spondylitis of cervical region |
| M453 | Ankylosing spondylitis of cervicothoracic region |
| M454 | Ankylosing spondylitis of thoracic region |
| M455 | Ankylosing spondylitis of thoracolumbar region |
| M456 | Ankylosing spondylitis lumbar region |
| M457 | Ankylosing spondylitis of lumbosacral region |
| M458 | Ankylosing spondylitis sacral and sacrococcygeal region |
| M459 | Ankylosing spondylitis of unspecified sites in spine |
| M45A | Non-radiographic axial spondyloarthritis |
| M45A0 | Non-radiographic axial spondyloarthritis of unspecified sites in spine |
| M45A1 | Non-radiographic axial spondyloarthritis occipt-atlan-ax rgn Non-radiographic axial spondyloarthritis of occipito-atlanto-axial region |
| M45A2 | Non-radiographic axial spondyloarthritis of cervical region |
| M45A3 | Non-radiographic axial spondyloarthritis of cervicothoracic region |
| M45A4 | Non-radiographic axial spondyloarthritis of thoracic region |
| M45A5 | Non-radiographic axial spondyloarthritis of thoracolumbar region |
| M45A6 | Non-radiographic axial spondyloarthritis of lumbar region |
| M45A7 | Non-radiographic axial spondyloarthritis of lumbosacr region Non-radiographic axial spondyloarthritis of lumbosacral region |
| M45A8 | Non-radiographic axial spondyloarthritis of sacral and sacrococcygeal region |
| M45AB | Non-radiographic axial spondyloarthritis of multiple sites in spine |
| M46 | Other inflammatory spondylopathies |
| M460 | Spinal enthesopathy |
| M4600 | Spinal enthesopathy, site unspecified |
| M4601 | Spinal enthesopathy, occipito-atlanto-axial region |
| M4602 | Spinal enthesopathy, cervical region |
| M4603 | Spinal enthesopathy, cervicothoracic region |
| M4604 | Spinal enthesopathy, thoracic region |
| M4605 | Spinal enthesopathy, thoracolumbar region |
| M4606 | Spinal enthesopathy, lumbar region |
| M4607 | Spinal enthesopathy, lumbosacral region |
| M4608 | Spinal enthesopathy, sacral and sacrococcygeal region |
| M4609 | Spinal enthesopathy, multiple sites in spine |
| M461 | Sacroiliitis, not elsewhere classified |
| M462 | Osteomyelitis of vertebra |
| M4620 | Osteomyelitis of vertebra, site unspecified |
| M4621 | Osteomyelitis of vertebra, occipito-atlanto-axial region |
| M4622 | Osteomyelitis of vertebra, cervical region |
| M4623 | Osteomyelitis of vertebra, cervicothoracic region |
| M4624 | Osteomyelitis of vertebra, thoracic region |