M05.861
BillableOther rheumatoid arthritis with rheumatoid factor of right knee
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
A type of rheumatoid arthritis affecting the right knee joint, confirmed by the presence of rheumatoid factor in the blood.
Coding Tips
- •Ensure documentation specifies right knee involvement before assigning this code
- •This code is specific to the knee joint and should not be used for other lower extremity joints
Clinical Significance
This code captures other specified manifestations of seropositive rheumatoid arthritis with positive rheumatoid factor, representing a systemic autoimmune condition with potential for progressive joint destruction and disability. Accurate capture is essential for risk adjustment as it reflects significant ongoing treatment burden including disease-modifying antirheumatic drugs, biologics, and regular laboratory monitoring.
Documentation Requirements
- ✓Clinical diagnosis of rheumatoid arthritis clearly documented by the treating provider
- ✓Rheumatoid factor lab result status (positive or negative) consistent with the code selected
- ✓Affected joint(s) specified with laterality (right, left, or bilateral)
- ✓Current disease status: active, in remission, or chronic stable
- ✓Current treatment plan including medications (disease-modifying antirheumatic drugs, biologics, nonsteroidal anti-inflammatory drugs)
- ✓Specification of the 'other' rheumatoid arthritis manifestation or feature that distinguishes it from standard presentations
- ✓Assessment and plan addressing rheumatoid arthritis at each encounter where it impacts care or treatment
Commonly Confused Codes
M05.7xx (Rheumatoid arthritis with rheumatoid factor without organ involvement, same site) — Use M05.7xx for the standard seropositive presentation without organ or systems involvementM06.0xx (Rheumatoid arthritis without rheumatoid factor, same site) — Use M06.0xx when rheumatoid factor is negativeM06.9 (Rheumatoid arthritis, unspecified) — A nonspecific code that does not indicate rheumatoid factor status; avoid when rheumatoid factor status is knownM05.0x-M05.6x (Rheumatoid arthritis with organ involvement such as Felty syndrome, rheumatoid lung, vasculitis) — Use these when extra-articular manifestations are documentedM19.x (Osteoarthritis) — Osteoarthritis is a degenerative, non-autoimmune condition; do not confuse with rheumatoid arthritis which is inflammatory and autoimmune
Code Hierarchy
└M05Rheumatoid arthritis with rheumatoid factor└M05.8Other rheumatoid arthritis with rheumatoid factor└M05.86Other rheumatoid arthritis with rheumatoid factor of knee└M05.861Other rheumatoid arthritis with rheumatoid factor of right knee
└M05.861Other rheumatoid arthritis with rheumatoid factor of right knee