M05.131 ICD-10-CM Code: Rheumatoid lung disease with rheumatoid arthritis of right wrist
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FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Inflammatory polyarthropathies (M05-M14)
M05.131
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceRheumatoid lung disease with rheumatoid arthritis of right wrist
Rheumatoid arthritis of the right wrist combined with lung disease caused by the rheumatoid condition.
Buddy Insight
Indicates severe rheumatoid arthritis with right wrist involvement and pulmonary complications, representing systemic disease with extra-articular manifestations.
CMS-HCC V28
MappedHCC 93
RAF 0.175
CMS-HCC V24
MappedHCC 40
RAF 0.307
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 40
RAF 0.0
RXHCC
MappedHCC 83
RAF 0.0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Rheumatoid lung disease with rheumatoid arthritis, carpal bones
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for M05.131 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for M05.131 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for M05.131 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for M05.131 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for M05.131 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for M05.131 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is M05.131 an HCC code?
Yes. M05.131 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 M05.131
For M05.131to 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 M05.131 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
M05.131 is the ICD-10-CM diagnosis code for rheumatoid lung disease with rheumatoid arthritis of right wrist. Rheumatoid arthritis of the right wrist combined with lung disease caused by the rheumatoid condition. M05.131 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, M05.131 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, M05.131 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.
Ensure documentation specifies right wrist involvement; this code is specific to the right side. Because M05.131 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 M05.131 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure documentation specifies right wrist involvement; this code is specific to the right side
- •Document the type of lung involvement (e.g., pulmonary fibrosis, pleural effusion) to support medical necessity
Clinical Significance
Indicates severe rheumatoid arthritis with right wrist involvement and pulmonary complications, representing systemic disease with extra-articular manifestations. This combination requires aggressive immunosuppressive management and careful monitoring for respiratory complications and functional decline.
Documentation Requirements
- ✓Confirmed rheumatoid arthritis with positive serological markers
- ✓Documentation of right wrist joint involvement with inflammatory changes
- ✓Evidence of rheumatoid-associated lung disease through appropriate testing
- ✓Specific notation of right-sided wrist involvement
- ✓Clinical assessment linking lung pathology to rheumatoid etiology
- ✓Current functional assessment and treatment response evaluation
- ✓Pulmonary monitoring including imaging and function studies
Commonly Confused Codes
- •M05.132: Rheumatoid lung disease with RA of left wrist (different laterality)
- •M05.139: Rheumatoid lung disease with RA of unspecified wrist (laterality not documented)
- •M06.031: Rheumatoid arthritis of right wrist without lung involvement
- •M05.141: Rheumatoid lung disease with RA of right hand (different anatomical site)
- •M05.121: Rheumatoid lung disease with RA of right elbow (different joint)