ICD-10 Code M05.36 – Rheumatoid heart disease with rheumatoid arthritis of knee (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M05.36 – Rheumatoid heart disease with rheumatoid arthritis of knee
What it is
This code identifies rheumatoid arthritis involving the knee in a patient who also has rheumatoid heart disease. It tells you the joint and cardiac complication are both documented.
Clinical signs
Expect documented knee pain, swelling, stiffness, or reduced motion consistent with rheumatoid arthritis. Rheumatoid heart disease may be noted by recognized cardiac involvement; clinical features vary, so refer to documentation.
When to use this code
Use this code when the record clearly states rheumatoid heart disease and rheumatoid arthritis affecting the knee in the same patient. You should assign it when the provider links the conditions or documents them together as part of the diagnosis.
If the knee involvement is unspecified or another joint is named, check documentation before coding. Do not assume heart disease is present without explicit provider support.
Do not use for
Do not use this code for rheumatoid arthritis without cardiac involvement, or for knee pain alone. Check documentation if the record describes a different joint or a non-rheumatoid heart condition.
Coding tip
Code only when both the rheumatoid heart disease and knee involvement are clearly documented in the same encounter or problem list.