M05.862
BillableOther rheumatoid arthritis with rheumatoid factor of left 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 left knee joint, confirmed by the presence of rheumatoid factor in the blood.
Coding Tips
- •Verify left knee is specifically documented in the clinical notes or imaging reports
- •Distinguish from bilateral knee involvement, which would require separate codes for each side
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└M05.862Other rheumatoid arthritis with rheumatoid factor of left knee
└M05.862Other rheumatoid arthritis with rheumatoid factor of left knee