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M05.A

Billable

Abnormal rheumatoid factor and anti-citrullinated protein antibody with rheumatoid arthritis

This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

Rheumatoid arthritis in patients who have abnormal blood test results showing both rheumatoid factor and anti-citrullinated protein antibodies, indicating a more aggressive form of the disease.

Coding Tips

  • This code indicates dual positive serology (both RF and anti-CCP antibodies present)
  • Document which joints are affected as this code may require additional site-specific codes depending on documentation

Code First

  • rheumatoid arthritis with rheumatoid factor by site, if known (M05.00 to M05.8A)

Code Hierarchy

M05Rheumatoid arthritis with rheumatoid factorM05.AAbnormal rheumatoid factor and anti-citrullinated protein antibody with rheumatoid arthritis
M05.AAbnormal rheumatoid factor and anti-citrullinated protein antibody with rheumatoid arthritis

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