What is ICD-10 code M86.30?

M86.30 is the ICD-10-CM diagnosis code for Chronic multifocal osteomyelitis, unspecified site. A long-standing bone infection affecting multiple bones throughout the body, with the specific location unspecified. It belongs to the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99). M86.30 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. M86.30 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. M86.30 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. M86.30 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 M86.30 map to under V28?

M86.30 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 M86.30: Chronic multifocal

M86.30 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 lookupM86.30

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)

M86.30

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

Chronic multifocal osteomyelitis, unspecified site

A long-standing bone infection affecting multiple bones throughout the body, with the specific location unspecified.

Buddy Insight

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

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

M86Osteomyelitis M86.3Chronic multifocal osteomyelitis M86.30Chronic multifocal osteomyelitis, unspecified site

Inclusion Terms

Official

No inclusion terms are included in this display for M86.30. Check the code and parent instructions in the Code Book.

Excludes 2

Official

arthropathic psoriasis (L40.5-)Inherited from M00-M99, M86
certain conditions originating in the perinatal period (P04-P96)Inherited from M00-M99, M86
certain infectious and parasitic diseases (A00-B99)Inherited from M00-M99, M86
compartment syndrome (traumatic) (T79.A-)Inherited from M00-M99, M86
complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from M00-M99, M86
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from M00-M99, M86
endocrine, nutritional and metabolic diseases (E00-E88)Inherited from M00-M99, M86
injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from M00-M99, M86
neoplasms (C00-D49)Inherited from M00-M99, M86
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from M00-M99, M86
ostemyelitis of:Inherited from M00-M99, M86
orbit (H05.0-)Inherited from M00-M99, M86
petrous bone (H70.2-)Inherited from M00-M99, M86
vertebra (M46.2-)Inherited from M00-M99, M86

Related Codes

Official

M86.31Chronic multifocal osteomyelitis, shoulder M86.32Chronic multifocal osteomyelitis, humerus M86.33Chronic multifocal osteomyelitis, radius and ulna M86.34Chronic multifocal osteomyelitis, hand M86.35Chronic multifocal osteomyelitis, femur

Includes

Official

No Includes notes are included in this display for M86.30. Check the code and parent instructions in the Code Book.

Excludes 1

Official

postprocedural osteopathies (M96.-)Inherited from M86-M90, M86
osteomyelitis due to:Inherited from M86-M90, M86
echinococcus (B67.2)Inherited from M86-M90, M86
gonococcus (A54.43)Inherited from M86-M90, M86
salmonella (A02.24)Inherited from M86-M90, M86

Code First

Official

No Code First sequencing instructions are included in this display for M86.30. Check the code and parent instructions in the Code Book.

Use Additional

Official

code (B95-B97) to identify infectious agentInherited from M86
code to identify major osseous defect, if applicable (M89.7-)Inherited from M86

Code Also

Official

No Code Also instructions are included in this display for M86.30. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Clear documentation of chronic multifocal osteomyelitis

Evidence of long-standing infection (typically months to years)

Documentation of involvement at multiple bone sites

Clinical evidence of chronic bone infection with systemic manifestations

MEAT Support

HCC Buddy guidance

Clear documentation of chronic multifocal osteomyelitis

Evidence of long-standing infection (typically months to years)

Documentation of involvement at multiple bone sites

Clinical evidence of chronic bone infection with systemic manifestations

Audit Caution

HCC Buddy guidance

Confusing chronic multifocal with other forms of chronic osteomyelitis

Failing to establish chronic timeline (months to years)

Using when infection involves only one or two sites

Missing documentation of multifocal involvement

Common Mistakes

HCC Buddy guidance

M86.29 — Use for subacute osteomyelitis at multiple sites

M86.69 — Use for other chronic osteomyelitis at multiple sites

M86.09 — Use for acute hematogenous osteomyelitis at multiple sites

M35.6 — Use for relapsing polychondritis without bone involvement

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 M86.30 an HCC code?

Yes. M86.30 (Chronic multifocal osteomyelitis, unspecified site) 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: M86.30 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: M86.30
Description: Chronic multifocal osteomyelitis, unspecified site
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

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 M86.30 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for M86.30

For M86.30, 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

M86.30 is the ICD-10-CM diagnosis code for chronic multifocal osteomyelitis, unspecified site. A long-standing bone infection affecting multiple bones throughout the body, with the specific location unspecified. M86.30 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, M86.30 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 M86.30; 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.

Request clarification from the provider regarding which bones are affected, as more specific codes exist for common sites. For M86.30, 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 M86.30 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Request clarification from the provider regarding which bones are affected, as more specific codes exist for common sites.
•Chronic multifocal osteomyelitis often requires investigation for underlying systemic conditions; ensure appropriate workup is documented.

Clinical Significance

Chronic multifocal osteomyelitis at unspecified site represents a long-standing bone infection affecting multiple locations throughout the body, indicating severe systemic disease with significant morbidity. This condition requires prolonged antibiotic therapy, potential surgical intervention, and comprehensive management to prevent complications such as pathologic fractures, sepsis, and permanent disability.