Rheu arthrit w rheu factor of unsp ank/ft w/o org/sys involv

This code signifies a diagnosis of seropositive rheumatoid arthritis affecting an unspecified ankle or foot, where there is no evidence of systemic complications or involvement of other organ systems. The presence of rheumatoid factor (RF) is a key diagnostic criterion for this specific type of rheumatoid arthritis.

Apply this code when documentation confirms a diagnosis of rheumatoid arthritis with positive rheumatoid factor, and the affected joint is an ankle or foot, without further specification of laterality. This code is appropriate when the medical record explicitly states the absence of extra-articular manifestations or organ involvement.

• Ensure documentation specifies "rheumatoid factor positive" to differentiate from seronegative forms.
• Avoid using this code if laterality (right or left ankle/foot) is documented; instead, use the more specific M05.771 or M05.772.
• Do not use this code if there is any mention of systemic complications (e.g., vasculitis, lung involvement); a more comprehensive code from the M05.3-M05.7 series would be appropriate.