M08.1 vs M45.0
M08.1 (Juvenile ankylosing spondylitis) compared with M45.0 (Ankylosing spondylitis of multiple sites in spine), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. M08.1 carries an Excludes1 note covering M45.0: “ankylosing spondylitis in adults (M45.0-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
No — do not report together. M45.0 carries an Excludes1 note covering M08.1: “juvenile (ankylosing) spondylitis (M08.1)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| M08.1Juvenile ankylosing spondylitis | M45.0Ankylosing spondylitis of multiple sites in spine | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) | M00-M99 — Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) |
| Definition | Juvenile ankylosing spondylitis is a billable ICD-10-CM diagnosis code (M08.1). | Ankylosing spondylitis of multiple sites in spine is a billable ICD-10-CM diagnosis code (M45.0). |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources