M45 ICD-10-CA code: Ankylosing spondylitis
M45 is the ICD-10-CA code for “Ankylosing spondylitis” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
M45Ankylosing spondylitis
ICD-10-CA · Canada
Index terms
Entries in CIHI’s alphabetical index that lead to M45. Searching the index by the condition the note names is how coders reach this code.
- Poker spine
- Bechterev's syndrome
- Bekhterev's syndrome
- Strümpell Marie spine
- Spondylitis, rheumatoid
- Spondylitis, rhizomelica
- Spondylitis, ankylopoietica
- Spondylitis, Marie Strümpell
- Spondylitis, ankylosing (chronic)
- Spondylitis, atrophic (ligamentous)
- Marie Strümpell arthritis, disease or spondylitis
- Arthritis, arthritic (acute) (chronic) (subacute), atrophic, spine
- Arthritis, arthritic (acute) (chronic) (subacute), rheumatoid, spine
- Arthritis, arthritic (acute) (chronic) (subacute), spine, rheumatoid
- Arthritis, arthritic (acute) (chronic) (subacute), spine, Marie Strümpell
- Arthritis, arthritic (acute) (chronic) (subacute), primary progressive, spine
- Arthritis, arthritic (acute) (chronic) (subacute), ankylosing (crippling) (spine)
Notes for M45
As CIHI prints them, with any note M45 takes from the headings above it.
Includes
- Rheumatoid arthritis of spine
Excludes
Conditions classified elsewhere.
- Arthropathy in Reiter disease (M02.3-)Behçet's disease (M35.2)juvenile (ankylosing) spondylitis (M08.1)
- Certain:• conditions originating in the perinatal period (P00-P96)• disorders of the temporomandibular joint (K07.6)• infectious and parasitic diseases (A00-B99)compartment syndrome (T79.6)complications of pregnancy, childbirth and the puerperium (O00-O99)congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E90)injury, poisoning and certain other consequences of external causes (S00-T98)neoplasms (C00-D48)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)From Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
Note
- The following fifth characters represent the following sites of involvement:0 Multiple sites1 Shoulder region: clavical , scapula — joint acromioclavicular, glenohumeral, sternoclavicular2 Upper arm: humerus — elbow joint,3 Forearm: radius , ulna — wrist joint,4 Hand: carpus, fingers, metacarpus — joints between these bones,5 Pelvic region and thigh: buttock , femur , pelvis — joint hip , sacroiliac6 Lower leg: fibula , tibia — knee joint7 Ankle and foot: metatarsus, tarsus, toes — other joints in foot8 Other:head neck ribs skull trunk vertebral column9 Site unspecifiedFrom Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
Where M45 sits
- 1ChapterChapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
- 2Block M40-M54Dorsopathies
- 3Block M45-M49Spondylopathies
- 4Valid code M45Ankylosing spondylitis
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code M45 mean?
M45 is the ICD-10-CA code for “Ankylosing spondylitis” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is M45 in ICD-10-CA?
M45 sits under M45-M49 Spondylopathies, within M40-M54 Dorsopathies, within Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99).
What coding notes apply to M45?
ICD-10-CA lists Includes, Excludes, Note notes for M45, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.