M05.00

Billable

Felty's syndrome, unspecified site

HCC Category Mapping

V28HCC 93 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.175

V24HCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.307

ESRDHCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.000

RxHCCHCC 83 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.000

What This Code Means

Felty's syndrome is a rare condition combining rheumatoid arthritis, enlarged spleen, and low white blood cell count, affecting multiple joints.

Coding Tips

•Felty's syndrome always includes rheumatoid arthritis; verify documentation mentions all three components (arthritis, splenomegaly, leukopenia)
•Use M05.00 only when the affected joint site is not specified; assign more specific codes if joint location is documented

Clinical Significance

Felty's syndrome represents a rare and serious complication of rheumatoid arthritis characterized by the triad of rheumatoid arthritis, splenomegaly, and neutropenia. This condition significantly increases infection risk and mortality, requiring intensive monitoring and specialized treatment including possible splenectomy or immunosuppressive therapy.

Documentation Requirements

✓Documentation of rheumatoid arthritis diagnosis
✓Evidence of splenomegaly (clinical or radiological)
✓Laboratory confirmation of neutropenia (ANC <1500/μL)
✓Documentation of the triad: RA + splenomegaly + neutropenia
✓Exclusion of other causes of neutropenia
✓Assessment of infection risk and complications
✓Documentation that specific joint site is unspecified
✓Evidence of systemic rheumatoid disease

Commonly Confused Codes

M05.0X1-M05.0X9 — Site-specific Felty's syndrome codes (when joint location documented)M06.9 — Rheumatoid arthritis, unspecified (RA without Felty's complications)D70.9 — Neutropenia, unspecified (neutropenia without RA/splenomegaly)R16.1 — Splenomegaly, not elsewhere classified (splenomegaly without RA)D73.1 — Hypersplenism (splenic dysfunction without full Felty's triad)

Code Hierarchy

└M05Rheumatoid arthritis with rheumatoid factor └M05.0Felty's syndrome └M05.00Felty's syndrome, unspecified site

└M05.00Felty's syndrome, unspecified site