M05.661
BillableRheumatoid arthritis of right knee with involvement of other organs and systems
HCC Category Mapping
V28HCC 93 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.175V24HCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.307ESRDHCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.000RxHCCHCC 83 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.000What This Code Means
Rheumatoid arthritis affecting the right knee with systemic complications involving other organs or body systems.
Coding Tips
- •Verify right knee is documented; this code indicates seropositive RA with extra-articular manifestations.
- •Document associated systemic features such as rheumatoid lung disease, cardiac involvement, or vasculitis when present.
Clinical Significance
This diagnosis indicates severe rheumatoid arthritis affecting the right knee with systemic organ involvement, representing advanced inflammatory disease requiring comprehensive management. The extra-articular manifestations significantly increase patient complexity and mortality risk beyond isolated joint disease.
Documentation Requirements
- ✓Confirmation of rheumatoid arthritis diagnosis in the right knee
- ✓Documentation of specific organ system involvement beyond joints
- ✓Evidence of extra-articular manifestations (pulmonary, cardiac, renal, ocular, etc.)
- ✓Laboratory confirmation of RA (rheumatoid factor, anti-CCP antibodies)
- ✓Clinical documentation of systemic disease activity and severity
- ✓Specific identification of affected organ systems
- ✓Clear attribution of systemic manifestations to rheumatoid arthritis
Commonly Confused Codes
M05661 vs M17.11 — M17.11 is unilateral primary osteoarthritis of right kneeM05661 vs M25.561 — M25.561 is right knee pain without inflammatory arthritisM05661 vs M06.9 — M06.9 is unspecified RA without required organ involvementM05661 vs M05662 — Incorrect laterality (left vs right knee)M05661 vs M13.161 — M13.161 is monoarthritis not elsewhere classified
Code Hierarchy
└M05Rheumatoid arthritis with rheumatoid factor└M05.6Rheumatoid arthritis with involvement of other organs and systems└M05.66Rheumatoid arthritis of knee with involvement of other organs and systems└M05.661Rheumatoid arthritis of right knee with involvement of other organs and systems
└M05.661Rheumatoid arthritis of right knee with involvement of other organs and systems