M05.739
BillableRheumatoid arthritis with rheumatoid factor of unspecified wrist without organ or systems involvement
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M05.739 an HCC code?
Yes. M05.739 maps to Rheumatoid Arthritis and Inflammatory Connective Tissue Disease under the CMS-HCC V28 risk adjustment model (and Rheumatoid Arthritis and Inflammatory Connective Tissue Disease under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for M05.739
For M05.739to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed M05.739 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M05.739 is the ICD-10-CM diagnosis code for rheumatoid arthritis with rheumatoid factor of unspecified wrist without organ or systems involvement. Rheumatoid arthritis affecting the wrist with a positive rheumatoid factor blood test when the specific side (left or right) is not documented, without involvement of other organs or body systems. M05.739 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering inflammatory polyarthropathies (m05-m14).
Under the CMS-HCC V28 risk adjustment model, M05.739 maps to Rheumatoid Arthritis and Inflammatory Connective Tissue Disease (HCC 93) with a community, non-dual, aged base RAF weight of 0.175. Under the older V24 model, M05.739 mapped to the same category but with a base RAF weight of 0.307 — V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Use this code only when laterality cannot be determined from documentation; query the provider if possible for clarification. Because M05.739 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for M05.739 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
This diagnosis captures seropositive rheumatoid arthritis affecting unspecified wrist without systemic involvement, representing localized inflammatory disease when laterality cannot be determined from documentation. Given the functional importance of wrist joints, this still represents significant chronic disease requiring ongoing management.
Documentation Requirements
- ✓Confirmation of rheumatoid arthritis diagnosis affecting wrist joint
- ✓Positive rheumatoid factor laboratory result
- ✓Documentation that wrist laterality cannot be determined from available records
- ✓Confirmation that no organ or system involvement is present
- ✓Clinical evidence of inflammatory arthritis in wrist
- ✓Exclusion of extra-articular manifestations
- ✓Assessment of disease activity and functional impact
Commonly Confused Codes
- •M05739 vs M05731/M05732 — Use specific laterality when wrist side is documented
- •M05739 vs M19.039 — M19.039 is unspecified osteoarthritis of wrist
- •M05739 vs M25.539 — M25.539 is pain in unspecified wrist
- •M05739 vs M65.849 — M65.849 is tenosynovitis of unspecified wrist
- •M05739 vs M05.639 — M05.639 includes organ involvement