M05.00 Felty's syndrome, 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.-)

Applies from M05.0 Felty's syndrome

Applicable to

• Rheumatoid arthritis with splenoadenomegaly and leukopenia

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)

• 714.1 Felty's syndrome (approximate)

Code annotations containing back-references to M05.00

Back-references to M05.00

• Code First: J84.170 Interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere ("rheumatoid arthritis (M05.00-M06.9)")
• Code First: J84.178 Other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere ("rheumatoid arthritis (M05.00-M06.9)")
• Code First: M05.A Abnormal rheumatoid factor and anti-citrullinated protein antibody with rheumatoid arthritis ("rheumatoid arthritis with rheumatoid factor by site, if known (M05.00 to M05.8A)")

Back-references to M05.0

• Type 1 Excludes: M08 Juvenile arthritis ("Felty's syndrome (M05.0)")

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 M05.00

• Felty's syndrome

Nearby codes

• M05 Rheumatoid arthritis with rheumatoid factor
• M05.0 Felty's syndrome
• M05.00 Felty's syndrome, unspecified site (this code)
• M05.01 Felty's syndrome, shoulder
• M05.011 Felty's syndrome, right shoulder
• M05.012 Felty's syndrome, left shoulder
• M05.019 Felty's syndrome, unspecified shoulder
• M05.02 Felty's syndrome, elbow