M05.542 ICD-10-CM Code: Rheumatoid polyneuropathy with rheumatoid arthritis of left hand
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FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Inflammatory polyarthropathies (M05-M14)
M05.542
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceRheumatoid polyneuropathy with rheumatoid arthritis of left hand
A condition where rheumatoid arthritis affects the left hand and causes nerve damage in multiple areas of the body.
Buddy Insight
This represents a severe form of rheumatoid arthritis with neurological complications affecting the left hand, indicating advanced systemic disease.
CMS-HCC V28
MappedHCC 93
RAF 0.175
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
00
RAF 0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Rheumatoid polyneuropathy with rheumatoid arthritis, metacarpus and phalanges
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for M05.542 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for M05.542 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for M05.542 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for M05.542 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for M05.542 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for M05.542 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 M05.542 an HCC code?
Yes. M05.542 maps to Rheumatoid Arthritis and Inflammatory Connective Tissue Disease under the CMS-HCC V28 risk adjustment model.
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 M05.542
For M05.542to 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 M05.542 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
M05.542 is the ICD-10-CM diagnosis code for rheumatoid polyneuropathy with rheumatoid arthritis of left hand. A condition where rheumatoid arthritis affects the left hand and causes nerve damage in multiple areas of the body. M05.542 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, M05.542 maps to Rheumatoid Arthritis and Inflammatory Connective Tissue Disease (HCC 93) with a community, non-dual, aged base RAF weight of 0.175. M05.542 was not retained as a payment HCC under the older V24 model, so V28 introduced or recategorized it during the 2024–2026 phase-in. 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.
This code requires documentation of both rheumatoid arthritis and polyneuropathy affecting the left hand specifically. Because M05.542 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 M05.542 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code requires documentation of both rheumatoid arthritis and polyneuropathy affecting the left hand specifically
- •Verify laterality is documented as left; do not use this code if the hand side is unspecified or bilateral
Clinical Significance
This represents a severe form of rheumatoid arthritis with neurological complications affecting the left hand, indicating advanced systemic disease. The combination of joint involvement and polyneuropathy suggests significant inflammation requiring aggressive treatment and close monitoring for disease progression.
Documentation Requirements
- ✓Confirmed diagnosis of rheumatoid arthritis with positive serology or clinical criteria
- ✓Evidence of polyneuropathy through nerve conduction studies or clinical examination
- ✓Specific documentation of left hand joint involvement with inflammatory changes
- ✓Assessment of functional impairment and disability level
- ✓Documentation of systemic inflammation markers (ESR, CRP)
- ✓Neurological examination findings consistent with polyneuropathy
- ✓Treatment response and medication management details
- ✓Impact on activities of daily living
Commonly Confused Codes
- •M05.549: Use when hand laterality is not specified in documentation
- •M06.9: Simple rheumatoid arthritis without polyneuropathy component
- •G62.9: Polyneuropathy without documented rheumatoid arthritis connection
- •M79.3: Panniculitis without specific rheumatoid arthritis diagnosis
- •M25.542: Pain in left hand without confirmed rheumatoid arthritis