What is ICD-10 code M05.342?

M05.342 is the ICD-10-CM diagnosis code for Rheumatoid heart disease with rheumatoid arthritis of left hand. A condition where rheumatoid arthritis affects the left hand and also causes inflammation of the heart tissue (rheumatoid heart disease). M05.342 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. M05.342 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. M05.342 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. M05.342 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for M05.342?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For M05.342, V28 maps to Rheumatoid Arthritis and Inflammatory Connective Tissue Disease at RAF 0.175 while V24 mapped to Rheumatoid Arthritis and Inflammatory Connective Tissue Disease at RAF 0.307. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting M05.342?

Ensure documentation clearly specifies left hand involvement to differentiate from right hand codes Both cardiac and joint manifestations must be present in the clinical record Because M05.342 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

M05.342 ICD-10 Code: Rheumatoid heart disease

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupM05.342Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Inflammatory polyarthropathies (M05-M14)

M05.342

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Rheumatoid heart disease with rheumatoid arthritis of left hand

A condition where rheumatoid arthritis affects the left hand and also causes inflammation of the heart tissue (rheumatoid heart disease).

Buddy Insight

This diagnosis represents a complex systemic manifestation of rheumatoid arthritis affecting both the cardiovascular system and left hand.

CMS-HCC V28

Mapped

HCC 93

Rheumatoid Arthritis and Infl...

RAF 0.175

CMS-HCC V24

Mapped

HCC 40

Rheumatoid Arthritis and Infl...

RAF 0.307

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 40

Rheumatoid Arthritis and Infl...

RAF 0.0

RXHCC

Mapped

HCC 83

Rheumatoid Arthritis and Infl...

RAF 0.0

Code Trumping

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Code Book Path

Official

M05.3Rheumatoid heart disease with rheumatoid arthritis

M05.34Rheumatoid heart disease with rheumatoid arthritis of hand

M05.342Rheumatoid heart disease with rheumatoid arthritis of left hand

Inclusion Terms

Official

Rheumatoid heart disease with rheumatoid arthritis, metacarpus and phalanges

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for M05.342 in this effective period.

Related Child Codes

Official

M05.341Rheumatoid heart disease with rheumatoid arthritis of right hand

M05.349Rheumatoid heart disease with rheumatoid arthritis of unspecified hand

Includes

Official

ICD-10-CM does not list Includes notes for M05.342 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for M05.342 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for M05.342 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for M05.342 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for M05.342 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Confirmed diagnosis of rheumatoid arthritis with positive serology (RF or anti-CCP)

Evidence of cardiac involvement such as pericarditis, myocarditis, or valvular disease

Specific documentation of left hand joint involvement with inflammatory changes

Clinical assessment of hand deformities, grip strength, and functional limitations

MEAT Support

HCC Buddy guidance

Confirmed diagnosis of rheumatoid arthritis with positive serology (RF or anti-CCP)

Evidence of cardiac involvement such as pericarditis, myocarditis, or valvular disease

Specific documentation of left hand joint involvement with inflammatory changes

Clinical assessment of hand deformities, grip strength, and functional limitations

Audit Caution

HCC Buddy guidance

Confusing left versus right laterality in documentation and coding

Failing to document both cardiac and hand manifestations required for this combination code

Using when only general RA is present without specific cardiac involvement

Confusing hand versus wrist involvement when coding upper extremity RA

Common Mistakes

HCC Buddy guidance

M05.341 — Same condition but affecting right hand instead of left

M05.349 — Same condition but hand laterality unspecified

M05.332 — Rheumatoid heart disease with left wrist involvement (different joint)

M06.9 — Rheumatoid arthritis, unspecified (no heart involvement documented)

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 M05.342 an HCC code?

Yes. M05.342 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

V28HCC 93, Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.175

V24HCC 40, Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.307

ESRDHCC 40, Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.000

RxHCCHCC 83, Rheumatoid Arthritis and Inflammatory Connective Tissue Disease

0.000

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 M05.342

For M05.342to 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 M05.342 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

M05.342 is the ICD-10-CM diagnosis code for rheumatoid heart disease with rheumatoid arthritis of left hand. A condition where rheumatoid arthritis affects the left hand and also causes inflammation of the heart tissue (rheumatoid heart disease). M05.342 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, M05.342 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, M05.342 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 clearly specifies left hand involvement to differentiate from right hand codes. Because M05.342 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 M05.342 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Ensure documentation clearly specifies left hand involvement to differentiate from right hand codes
•Both cardiac and joint manifestations must be present in the clinical record

Clinical Significance

This diagnosis represents a complex systemic manifestation of rheumatoid arthritis affecting both the cardiovascular system and left hand. The combination of rheumatoid heart disease with hand involvement indicates advanced inflammatory disease that significantly impacts patient function and quality of life, requiring comprehensive management including cardiac monitoring and aggressive immunosuppression.

Documentation Requirements

✓Confirmed diagnosis of rheumatoid arthritis with positive serology (RF or anti-CCP)
✓Evidence of cardiac involvement such as pericarditis, myocarditis, or valvular disease
✓Specific documentation of left hand joint involvement with inflammatory changes
✓Clinical assessment of hand deformities, grip strength, and functional limitations
✓Echocardiogram or other cardiac imaging showing rheumatoid heart disease
✓Laboratory evidence of systemic inflammation (elevated ESR, CRP)
✓Documentation of chronicity and ongoing disease activity
✓Treatment with DMARDs or biologic agents

Commonly Confused Codes

•M05.341: Same condition but affecting right hand instead of left
•M05.349: Same condition but hand laterality unspecified
•M05.332: Rheumatoid heart disease with left wrist involvement (different joint)
•M06.9: Rheumatoid arthritis, unspecified (no heart involvement documented)