M46.91 ICD-10-CA code: Inflammatory spondylopathy, unspecified, occipito-atlanto-axial region

M46.91 is the ICD-10-CA code for “Inflammatory spondylopathy, unspecified, occipito-atlanto-axial region” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.

Official description

M46.91

Inflammatory spondylopathy, unspecified, occipito-atlanto-axial region

Short description: Inf spondylopathy NOS ocptatlntaxl

ICD-10-CA · Canada · Also written M4691

Notes for M46.91

As CIHI prints them, with any note M46.91 takes from the headings above it.

Excludes

Conditions classified elsewhere.

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 M46.91 sits

1ChapterChapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
2Block M40-M54Dorsopathies
3Block M45-M49Spondylopathies
4Category M46Other inflammatory spondylopathies
5Subcategory M46.9Inflammatory spondylopathy, unspecified
6Valid code M46.91Inflammatory spondylopathy, unspecified, occipito-atlanto-axial region

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.

See M46.91 in the CIHI source

Frequently asked questions

What does ICD-10-CA code M46.91 mean?

M46.91 is the ICD-10-CA code for “Inflammatory spondylopathy, unspecified, occipito-atlanto-axial region” in CIHI’s ICD-10-CA FY 2026–2027 release.

Where is M46.91 in ICD-10-CA?

M46.91 sits under M46.9 Inflammatory spondylopathy, unspecified, within M46 Other inflammatory spondylopathies, within 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 M46.91?

ICD-10-CA lists Note, Excludes notes for M46.91, 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.

View M46.9