M87.133 ICD-10-CM Code: Osteonecrosis due to drugs of unspecified radius
M87.133 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · HCC coding software
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FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Other osteopathies (M86-M90)
M87.133
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceOsteonecrosis due to drugs of unspecified radius
Death of bone tissue in the radius (forearm bone) caused by medication side effects when the specific side is not specified.
Buddy Insight
Drug-induced osteonecrosis of unspecified radius indicates medication-related bone death when laterality cannot be determined from documentation.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
MappedHCC 39
RAF 0.401
ACA/HHS
MappedHCC 55
Varies by metal level
ESRD/PACE
MappedHCC 39
RAF 0.092
RXHCC
MappedHCC 80
RAF 0.204
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for M87.133 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for M87.133 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for M87.133 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for M87.133 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for M87.133 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for M87.133 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for M87.133 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is M87.133 an HCC code?
Yes. M87.133 maps to Bone/Joint/Muscle Infections/Necrosis under the V24 model but is not retained in V28.
- Code
- M87.133
- Description
- Osteonecrosis due to drugs of unspecified radius
- HCC (V28)
- No CMS-HCC V28 mapping
- RAF
- —
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. 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.
Work M87.133 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for M87.133
For M87.133 to 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 M87.133 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
M87.133 is the ICD-10-CM diagnosis code for osteonecrosis due to drugs of unspecified radius. Death of bone tissue in the radius (forearm bone) caused by medication side effects when the specific side is not specified. M87.133 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 older CMS-HCC V24 model, M87.133 maps to Bone/Joint/Muscle Infections/Necrosis (HCC 39) with a community, non-dual, aged base RAF weight of 0.401. 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.
Use only when laterality cannot be determined from documentation; query provider if possible to obtain specific side. Because M87.133 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 M87.133 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use only when laterality cannot be determined from documentation; query provider if possible to obtain specific side
- •This code is less specific and may affect reimbursement; bilateral involvement requires separate codes for each side
Clinical Significance
Drug-induced osteonecrosis of unspecified radius indicates medication-related bone death when laterality cannot be determined from documentation. This diagnosis still carries significant implications for forearm function and requires comprehensive management despite the lack of side specification.
Documentation Requirements
- ✓Clear documentation that radius bone is affected by osteonecrosis
- ✓Specific drug or medication class identified as causative agent
- ✓Imaging evidence supporting osteonecrosis diagnosis
- ✓Clinical presentation including pain and functional limitations
- ✓Documentation explaining why laterality cannot be determined
- ✓Treatment approach regardless of side specification
- ✓Drug exposure history and temporal relationship to symptoms
- ✓Provider statement confirming drug-induced etiology
Commonly Confused Codes
- •M87.131/M87.132: Use specific laterality codes when right/left is documented
- •M87.233: Post-traumatic unspecified radius requires injury documentation
- •M87.033: Idiopathic osteonecrosis lacks drug causation requirement
- •M87.136: Unspecified ulna osteonecrosis affects different forearm bone
- •M87.9: Completely unspecified osteonecrosis lacks bone and drug specificity