M86.031 ICD-10-CM Code: Acute hematogenous osteomyelitis, right radius and ulna
HCC Buddy Code Card
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FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Other osteopathies (M86-M90)
M86.031
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAcute hematogenous osteomyelitis, right radius and ulna
A serious bone infection of the right forearm bones (radius and ulna) caused by bacteria spreading through the bloodstream.
Buddy Insight
Acute hematogenous osteomyelitis of right radius and ulna represents serious bloodstream-spread infection to both forearm bones, creating complex management challenges due to dual bone involvement.
CMS-HCC V28
MappedHCC 92
RAF 0.209
CMS-HCC V24
MappedHCC 39
RAF 0.482
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 39
RAF 0.0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for M86.031 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for M86.031 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for M86.031 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for M86.031 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for M86.031 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for M86.031 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for M86.031 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 M86.031 an HCC code?
Yes. M86.031 maps to Bone/Joint/Muscle Infections/Necrosis under the CMS-HCC V28 risk adjustment model (and Bone/Joint/Muscle Infections/Necrosis 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 M86.031
For M86.031to 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 M86.031 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
M86.031 is the ICD-10-CM diagnosis code for acute hematogenous osteomyelitis, right radius and ulna. A serious bone infection of the right forearm bones (radius and ulna) caused by bacteria spreading through the bloodstream. M86.031 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering other osteopathies (m86-m90).
Under the CMS-HCC V28 risk adjustment model, M86.031 maps to Bone/Joint/Muscle Infections/Necrosis (HCC 92) with a community, non-dual, aged base RAF weight of 0.209. Under the older V24 model, M86.031 mapped to the same category but with a base RAF weight of 0.482, 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.
This code covers both the radius and ulna bones of the forearm as a combined site. Because M86.031 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 M86.031 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code covers both the radius and ulna bones of the forearm as a combined site
- •Ensure documentation specifies right forearm to distinguish from left side infection
Clinical Significance
Acute hematogenous osteomyelitis of right radius and ulna represents serious bloodstream-spread infection to both forearm bones, creating complex management challenges due to dual bone involvement. This diagnosis indicates high risk for compartment syndrome, functional impairment, and chronic complications affecting wrist and elbow function.
Documentation Requirements
- ✓Documentation of acute osteomyelitis affecting right radius and ulna
- ✓Evidence of hematogenous spread to forearm bones
- ✓Clinical findings of right forearm swelling, pain, dysfunction
- ✓Imaging studies showing infection in both radius and ulna
- ✓Blood cultures and bone cultures when available
- ✓Treatment with IV antibiotics and possible surgical debridement
- ✓Assessment for compartment syndrome and neurovascular status