M05.80 Other rheumatoid arthritis with rheumatoid factor of unspecified site

Billable ICD-10-CM code, FY2026.

Applies from M05 Rheumatoid arthritis with rheumatoid factor

Excludes1 (never code together)

• rheumatic fever (I00)
• juvenile rheumatoid arthritis (M08.-)
• rheumatoid arthritis of spine (M45.-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 93 — Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders
• CMS-HCC V22: HCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
• RxHCC V08: HCC 83 — Rheumatoid Arthritis and Other Inflammatory Polyarthropathy
• ESRD V24: HCC 40

MS-DRG index

Defines the logic of DRG(s) 545-547 in MDC 08.

Approximate ICD-9-CM (GEMs)

• 714.0 Rheumatoid arthritis (approximate)

Code annotations containing back-references to M05.80

Back-references to M05

• Code Also: I27.21 Secondary pulmonary arterial hypertension ("rheumatoid arthritis (M05.-)")
• Type 1 Excludes: R76.81 Abnormal rheumatoid factor and anti-citrullinated protein antibody without rheumatoid arthritis ("rheumatoid arthritis with rheumatoid factor (M05.-)")

Diagnosis Index entries for M05.80

• Arthritis, arthritic (acute) (chronic) (nonpyogenic) (subacute) › rheumatoid › seropositive › specified NEC

Nearby codes

• M05.772 Rheumatoid arthritis with rheumatoid factor of left ankle and foot without organ or systems involvement
• M05.779 Rheumatoid arthritis with rheumatoid factor of unspecified ankle and foot without organ or systems involvement
• M05.79 Rheumatoid arthritis with rheumatoid factor of multiple sites without organ or systems involvement
• M05.7A Rheumatoid arthritis with rheumatoid factor of other specified site without organ or systems involvement
• M05.8 Other rheumatoid arthritis with rheumatoid factor
• M05.80 Other rheumatoid arthritis with rheumatoid factor of unspecified site (this code)
• M05.81 Other rheumatoid arthritis with rheumatoid factor of shoulder
• M05.811 Other rheumatoid arthritis with rheumatoid factor of right shoulder
• M05.812 Other rheumatoid arthritis with rheumatoid factor of left shoulder
• M05.819 Other rheumatoid arthritis with rheumatoid factor of unspecified shoulder
• M05.82 Other rheumatoid arthritis with rheumatoid factor of elbow