What is ICD-10 code M87.032?

M87.032 is the ICD-10-CM diagnosis code for Idiopathic aseptic necrosis of left radius. Death of bone tissue without infection in the left forearm bone (radius), occurring without a known cause. It belongs to the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99). M87.032 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. M87.032 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. M87.032 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. M87.032 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.

Which HCC does M87.032 map to under V28?

M87.032 maps to CMS-HCC V28 HCC 92 (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM M87.032: Idiopathic aseptic necrosis

M87.032 maps to CMS-HCC V28 92. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools

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Code lookupM87.032

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the musculoskeletal system and connective tissue (M00-M99) / Other osteopathies (M86-M90)

M87.032

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

Idiopathic aseptic necrosis of left radius

Death of bone tissue without infection in the left forearm bone (radius), occurring without a known cause.

Buddy Insight

Idiopathic aseptic necrosis of the left radius involves bone death in the forearm without known cause, potentially compromising wrist stability and hand function.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 92

Bone/Joint/Muscle/Severe Soft...

Code-level coefficient reference

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 055

HHS-HCC 055 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 39

Bone/Joint/Muscle Infections/...

Code-level coefficient reference

RXHCC

Mapped

HCC 80

Aseptic Necrosis of Bone

Code-level coefficient reference

Code Book Path

Official

M87.0Idiopathic aseptic necrosis of bone M87.03Idiopathic aseptic necrosis of radius, ulna and carpus M87.032Idiopathic aseptic necrosis of left radius

Inclusion Terms

Official

No inclusion terms are included in this display for M87.032. Check the code and parent instructions in the Code Book.

Excludes 2

Official

arthropathic psoriasis (L40.5-)Inherited from M00-M99
certain conditions originating in the perinatal period (P04-P96)Inherited from M00-M99
certain infectious and parasitic diseases (A00-B99)Inherited from M00-M99
compartment syndrome (traumatic) (T79.A-)Inherited from M00-M99
complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from M00-M99
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from M00-M99
endocrine, nutritional and metabolic diseases (E00-E88)Inherited from M00-M99
injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from M00-M99
neoplasms (C00-D49)Inherited from M00-M99
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from M00-M99

Related Codes

Official

M87.031Idiopathic aseptic necrosis of right radius M87.033Idiopathic aseptic necrosis of unspecified radius M87.034Idiopathic aseptic necrosis of right ulna M87.035Idiopathic aseptic necrosis of left ulna M87.036Idiopathic aseptic necrosis of unspecified ulna

Includes

Official

avascular necrosis of boneInherited from M87

Excludes 1

Official

postprocedural osteopathies (M96.-)Inherited from M86-M90, M87
juvenile osteonecrosis (M91-M92)Inherited from M86-M90, M87
osteochondropathies (M90-M93)Inherited from M86-M90, M87

Code First

Official

No Code First sequencing instructions are included in this display for M87.032. Check the code and parent instructions in the Code Book.

Use Additional

Official

code to identify major osseous defect, if applicable (M89.7-)Inherited from M87

Code Also

Official

No Code Also instructions are included in this display for M87.032. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Clear documentation of aseptic necrosis involving left radius bone

Confirmation of idiopathic nature without identifiable underlying cause

Radiological evidence showing bone necrosis in left radial structures

Specific laterality documentation indicating left side involvement

MEAT Support

HCC Buddy guidance

Clear documentation of aseptic necrosis involving left radius bone

Confirmation of idiopathic nature without identifiable underlying cause

Radiological evidence showing bone necrosis in left radial structures

Specific laterality documentation indicating left side involvement

Audit Caution

HCC Buddy guidance

Reversing laterality when documentation clearly states left radius

Defaulting to unspecified when laterality is explicitly documented

Missing drug-induced causes requiring M87.132 code assignment

Overlooking trauma etiology that would change code selection

Common Mistakes

HCC Buddy guidance

M87.031 — Right radius when laterality is incorrectly assigned

M87.033 — Unspecified radius when left side is documented

M87.132 — Drug-induced left radius osteonecrosis

M87.232 — Trauma-related left radius osteonecrosis

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 M87.032 an HCC code?

Yes. M87.032 (Idiopathic aseptic necrosis of left radius) maps to HCC 92, Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.479. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: M87.032 is billable and maps to V28 HCC 92, Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: M87.032
Description: Idiopathic aseptic necrosis of left radius
HCC (V28): HCC 92 — Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis
RAF reference coefficient: 0.479
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 92, Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis

0.479

ESRDHCC 39, Bone/Joint/Muscle Infections/Necrosis

Not separately weighted

RxHCCHCC 80, Aseptic Necrosis of Bone

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. 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 context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work M87.032 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for M87.032

For M87.032, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

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

Coder workflow notes

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What This Code Means

M87.032 is the ICD-10-CM diagnosis code for idiopathic aseptic necrosis of left radius. Death of bone tissue without infection in the left forearm bone (radius), occurring without a known cause. M87.032 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, M87.032 maps to Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis (HCC 92) with a source-labeled community, non-dual, aged reference coefficient of 0.479. No V24 mapping is shown for M87.032; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Verify the affected bone is the radius and not the ulna or other forearm structure. For M87.032, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, and MEAT documentation criteria for M87.032 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Verify the affected bone is the radius and not the ulna or other forearm structure
•Confirm left side is clearly documented in the clinical record

Clinical Significance

Idiopathic aseptic necrosis of the left radius involves bone death in the forearm without known cause, potentially compromising wrist stability and hand function. This serious orthopedic condition often requires comprehensive management including pain control, functional preservation, and possible surgical intervention to prevent progressive bone collapse.