ICD-10 Code M05.659 – Rheumatoid arthritis of unspecified hip with involvement of other organs and systems (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.659 – Rheumatoid arthritis of unspecified hip with involvement of other organs and systems
What it is
This code identifies rheumatoid arthritis affecting an unspecified hip and documented as involving other organs or systems. Use it when the hip site is stated, but the record does not specify left or right.
Clinical signs
Typical findings include inflammatory joint pain, stiffness, and reduced hip range of motion. Clinical features vary; refer to documentation for the extra-articular organ or system involvement.
When to use this code
Use this code when the provider documents rheumatoid arthritis of the hip and also notes involvement of other organs or systems, such as systemic disease manifestations. It fits when laterality is not specified. If the chart names a different joint or does not confirm systemic involvement, check documentation.
Do not use for
Do not use it for rheumatoid arthritis of a specified hip side, or for hip pain without confirmed rheumatoid arthritis. Do not assign it if the record lacks documentation of other organ or system involvement.
Coding tip
Confirm both the hip site and the extra-articular involvement before coding; if either element is missing, query the provider.