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M13.91 ICD-10-CA code: Arthritis, unspecified, shoulder region

M13.91 is the ICD-10-CA code for “Arthritis, unspecified, shoulder region” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.

Official description

M13.91

Arthritis, unspecified, shoulder region

Short description: Arthritis unspecified shoulder region

ICD-10-CA · Canada · Also written M1391

Notes for M13.91

As CIHI prints them, with any note M13.91 takes from the headings above it.

Includes

Excludes

Conditions classified elsewhere.

  • Arthrosis (M15-M19)From M13 Other arthritis
  • 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

  • [To review the anatomical site captured in the 5th character subclassification see Chapter XIII]From M13.9 Arthritis, unspecified
  • 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 M13.91 sits

  1. 1ChapterChapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99)
  2. 2Block M00-M25Arthropathies
  3. 3Block M05-M14Inflammatory polyarthropathies
  4. 4Category M13Other arthritis
  5. 5Subcategory M13.9Arthritis, unspecified
  6. 6Valid code M13.91Arthritis, unspecified, shoulder 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 M13.91 in the CIHI source

Frequently asked questions

What does ICD-10-CA code M13.91 mean?

M13.91 is the ICD-10-CA code for “Arthritis, unspecified, shoulder region” in CIHI’s ICD-10-CA FY 2026–2027 release.

Where is M13.91 in ICD-10-CA?

M13.91 sits under M13.9 Arthritis, unspecified, within M13 Other arthritis, within M05-M14 Inflammatory polyarthropathies, within M00-M25 Arthropathies, within Chapter 13: Diseases of the musculoskeletal system and connective tissue (M00-M99).

What coding notes apply to M13.91?

ICD-10-CA lists Note, Excludes, Includes notes for M13.91, 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.

Codes beside M13.91

M13.90Arthritis, unspecified, multiple sitesM13.92Arthritis, unspecified, upper armM13.93Arthritis, unspecified, forearmM13.94Arthritis, unspecified, handM13.95Arthritis, unspecified, pelvic region and thighM13.96Arthritis, unspecified, lower legM13.97Arthritis, unspecified, ankle and footM13.98Arthritis, unspecified, other siteM13.99Arthritis, unspecified, unspecified site