Question 1

What is ICD-10 code M90.58?

Accepted Answer

M90.58 is the ICD-10-CM diagnosis code for Osteonecrosis in diseases classified elsewhere, other site. Bone death (osteonecrosis) in other bone locations caused by another disease. The bone tissue dies as a secondary effect of an underlying condition in sites not covered by other specific codes. M90.58 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. M90.58 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.

Question 2

Is M90.58 an HCC code?

Accepted Answer

Yes. The final FY2026 CMS mapping file maps M90.58 to HCC 92 (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis) under CMS-HCC V28 with source-labeled reference coefficients HCC 92 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.

Question 3

Is M90.58 billable?

Accepted Answer

Yes. M90.58 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. M90.58 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.

Question 4

Which HCC does M90.58 map to under V28?

Accepted Answer

M90.58 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.

Question 5

What RAF reference is published for M90.58?

Accepted Answer

M90.58 has source-labeled community, non-dual, aged reference coefficients HCC 92 0.479 under CMS-HCC V28 for payment year 2026.  The coefficients come from the CMS V28 relative-factor file. 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.

Question 6

What is the V28 vs V24 difference for M90.58?

Accepted Answer

For M90.58, the current CMS-HCC V28 result is HCC 92 (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis). Select a historical effective period before comparing a V24 mapping.  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.

Question 7

What documentation supports M90.58?

Accepted Answer

Use this code for osteonecrosis in unusual or multiple specific sites not captured by other M90.5x codes Requires a secondary diagnosis code for the underlying disease causing the osteonecrosis For M90.58, 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. See the MEAT criteria checklist at /meat-criteria for what Monitor, Evaluate, Assess, or Treat looks like in a note. One mnemonic element does not establish that a diagnosis is reportable.

Question 8

Can M90.58 be a primary diagnosis?

Accepted Answer

No. M90.58 is a manifestation code, so it is never the first-listed diagnosis. The tabular instruction is to code first underlying disease, such as: caisson disease (T70.3); hemoglobinopathy (D50-D64), then report M90.58 as a secondary code. Sequencing does not change its CMS-HCC V28 category.

Question 9

Which codes cannot be reported with M90.58?

Accepted Answer

The Excludes1 note that applies to M90.58 lists postprocedural osteopathies (M96.-); osteochondritis, osteomyelitis, and osteopathy (in): cryptococcosis (B45.3); diabetes mellitus (E08-E13 with .69-); gonococcal (A54.43); and 5 more (see the notes on this page). An Excludes1 condition is not reported together with M90.58; report one or the other, unless the two conditions are unrelated, which the ICD-10-CM Official Guidelines (Section I.A.12.a) allow. The Excludes2 note lists arthropathic psoriasis (L40.5-); certain conditions originating in the perinatal period (P04-P96); certain infectious and parasitic diseases (A00-B99); compartment syndrome (traumatic) (T79.A-); and 6 more (see the notes on this page); those are separate conditions that may be reported together with M90.58 when both are documented.

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M90.58 ICD-10-CM Code: Osteonecrosis in diseases classified elsewhere, other site

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M90.58

Is M90.58 an HCC code?

HCC Category Mapping

MEAT review for M90.58

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What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Commonly Confused Codes

Child Codes

Code Hierarchy

Also searched as

Work M90.58 in HCC Buddy