M05.072 ICD-10-CM Code: Felty's syndrome, left ankle and foot
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FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Inflammatory polyarthropathies (M05-M14)
M05.072
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceFelty's syndrome, left ankle and foot
Felty's syndrome affecting the left ankle and foot, a condition combining rheumatoid arthritis with an enlarged spleen and low white blood cell count.
Buddy Insight
Felty's syndrome involving the left ankle and foot creates a complex medical scenario combining severe ambulatory impairment with dangerous immune dysfunction requiring immediate specialized intervention.
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- Felty's syndrome, tarsus, metatarsus and phalanges
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for M05.072 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for M05.072 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for M05.072 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for M05.072 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for M05.072 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for M05.072 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 M05.072 an HCC code?
Yes. M05.072 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 M05.072
For M05.072to 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 M05.072 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
M05.072 is the ICD-10-CM diagnosis code for felty's syndrome, left ankle and foot. Felty's syndrome affecting the left ankle and foot, a condition combining rheumatoid arthritis with an enlarged spleen and low white blood cell count. M05.072 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, M05.072 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, M05.072 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.
Felty's syndrome is a specific manifestation of rheumatoid arthritis; ensure the diagnosis documentation clearly states Felty's syndrome rather than just RA. Because M05.072 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 M05.072 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Felty's syndrome is a specific manifestation of rheumatoid arthritis; ensure the diagnosis documentation clearly states Felty's syndrome rather than just RA
- •The seventh character specifies laterality (left ankle/foot); verify documentation confirms left-sided involvement
Clinical Significance
Felty's syndrome involving the left ankle and foot creates a complex medical scenario combining severe ambulatory impairment with dangerous immune dysfunction requiring immediate specialized intervention. This condition demands comprehensive care coordination due to the critical weight-bearing involvement and life-threatening hematologic complications.
Documentation Requirements
- ✓Clear documentation of rheumatoid arthritis specifically affecting left ankle and foot
- ✓Evidence of splenomegaly through examination or imaging studies
- ✓Laboratory confirmation of neutropenia with specific white blood cell counts
- ✓Left ankle and foot laterality explicitly documented
- ✓Assessment of ambulatory function and weight-bearing capacity
- ✓History of infections or immunocompromised complications
- ✓Treatment plan including immunomodulatory therapy and monitoring
- ✓Podiatric care and orthotic device needs assessment
Commonly Confused Codes
- •M05.071: Same condition but affecting right ankle and foot instead of left
- •M05.9: Seropositive rheumatoid arthritis without the complete Felty's triad
- •M19.072: Primary osteoarthritis of left ankle and foot without inflammatory component
- •D70.4: Cyclic neutropenia without rheumatoid arthritis component
- •M25.572: Pain in left ankle and foot without systemic involvement