M05.8A
✓ BillableOther rheumatoid arthritis with rheumatoid factor of other specified site
Diseases of the musculoskeletal system and connective tissue (M00-M99)
❌ Excludes1
inheritedRules inherited from parent codes in the hierarchy.
- • rheumatic fever (I00)
- • juvenile rheumatoid arthritis (M08.-)
- • rheumatoid arthritis of spine (M45.-)
Clinical Description
ICD-10-CM code M05.8A represents other rheumatoid arthritis with rheumatoid factor of other specified site. This code falls under the Diseases of the musculoskeletal system and connective tissue (M00-M99) classification. It is a billable/specific code valid for HIPAA-covered transactions as of October 1, 2025 (FY2026). This code can be used to indicate a diagnosis for reimbursement purposes on insurance claims.
This is a 6-character code at the 5th level of specificity. This is the most specific code available in this subcategory. Coders should note that M05.8A has 3 Excludes1 restriction(s) — codes that cannot be reported together on the same claim.
Frequently Asked Questions
What is ICD-10 code M05.8A?
ICD-10-CM code M05.8A is "Other rheumatoid arthritis with rheumatoid factor of other specified site". It belongs to the category: Diseases of the musculoskeletal system and connective tissue (M00-M99).
Is M05.8A a billable ICD-10 code?
Yes, M05.8A is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
What codes are excluded with M05.8A?
M05.8A has 3 Excludes1 rule(s). These codes are mutually exclusive and cannot be coded together on the same claim.
Related Codes in M05.8
Other codes in the same category that may be relevant for differential coding:
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Data Source
CMS ICD-10-CM 2026 Tabular List
Updated October 1, 2025 (FY2026)