M05.662
BillableRheumatoid arthritis of left 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 left knee with systemic complications involving other organs or body systems.
Coding Tips
- •Confirm left knee is the affected site; this code encompasses both joint and systemic disease manifestations.
- •If patient has bilateral knee involvement, assign both M05.661 and M05.662 to capture complete clinical picture.
Clinical Significance
This code represents systemic rheumatoid arthritis affecting the left knee with organ system involvement, indicating advanced inflammatory disease with significant patient morbidity. The systemic component elevates this beyond simple arthritis to a complex multi-system condition requiring intensive management.
Documentation Requirements
- ✓Confirmation of rheumatoid arthritis diagnosis affecting the left knee
- ✓Documentation of organ or system involvement beyond the knee joint
- ✓Evidence of extra-articular manifestations (cardiovascular, pulmonary, etc.)
- ✓Laboratory support for RA diagnosis (RF, anti-CCP, inflammatory markers)
- ✓Clinical assessment documenting systemic disease activity
- ✓Specific identification of affected organ systems beyond joints
- ✓Clear relationship between systemic involvement and rheumatoid arthritis
Commonly Confused Codes
M05662 vs M17.12 — M17.12 is unilateral primary osteoarthritis of left kneeM05662 vs M25.562 — M25.562 is left knee pain without inflammatory componentM05662 vs M05661 — Wrong laterality (right vs left knee)M05662 vs M06.9 — M06.9 lacks the required organ involvement specificationM05662 vs M13.162 — M13.162 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└M05.662Rheumatoid arthritis of left knee with involvement of other organs and systems
└M05.662Rheumatoid arthritis of left knee with involvement of other organs and systems