M45.1 – Ankylosing spondylitis of occipito-atlanto-axial region
ICD-10-CM 2027 diagnosis code · Spondylopathies
ICD-10-CM code
M45.1
- Code
M45.1(claims format:M451)- Description
- Ankylosing spondylitis of occipito-atlanto-axial region
- Billable
- Yes – valid for HIPAA-covered transactions
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 13. Diseases of the musculoskeletal system and connective tissue (M00-M99)
- Block
- M45-M49 Spondylopathies
- Parent codes
- M45
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
M45 – Ankylosing spondylitis
Applicable to:
- Rheumatoid arthritis of spine
Excludes1 (not coded here):
Excludes2 (not included here):
- Behçet's disease (M35.2)
Index terms for M45.1
Entries in the ICD-10-CM alphabetic index that lead to this code:
Related codes in M45
- M45.0 – Ankylosing spondylitis of multiple sites in spineBillable
- M45.2 – Ankylosing spondylitis of cervical regionBillable
- M45.3 – Ankylosing spondylitis of cervicothoracic regionBillable
- M45.4 – Ankylosing spondylitis of thoracic regionBillable
- M45.5 – Ankylosing spondylitis of thoracolumbar regionBillable
- M45.6 – Ankylosing spondylitis lumbar regionBillable
- M45.7 – Ankylosing spondylitis of lumbosacral regionBillable
- M45.8 – Ankylosing spondylitis sacral and sacrococcygeal regionBillable
- M45.9 – Ankylosing spondylitis of unspecified sites in spineBillable
- M45.A – Non-radiographic axial spondyloarthritisHeader
Frequently asked questions
What is ICD-10 code M45.1?
M45.1 is the ICD-10-CM code for ankylosing spondylitis of occipito-atlanto-axial region, in the block M45-M49 (Spondylopathies).
Is M45.1 a billable code?
Yes. M45.1 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.
What category does M45.1 belong to?
It belongs to category M45 – Ankylosing spondylitis.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.