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M86.252 ICD-10-CM Code: Subacute osteomyelitis, left femur

M86.252 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 lookupM86.252

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

M86.252

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

Subacute osteomyelitis, left femur

A bone infection in the left thighbone (femur) that develops gradually over weeks to months.

Buddy the Bee presenting code insight

Buddy Insight

Subacute osteomyelitis of the left femur is an intermediate-stage bone infection that develops gradually over weeks to months, potentially causing significant functional impairment and risk of progression to chronic infection.

CMS-HCC V28

HCC 92

Coefficient HCC 92: 0.479 (Community Non-Dual Aged (CNA))

CMS-HCC V24

Historical

Historical

Not used for CY2026 payment

ACA/HHS

HCC 055

Code-level coefficient reference

ESRD/PACE

HCC 39

Code-level coefficient reference

RXHCC

N/A

Not mapped

Inclusion Terms

Official

No inclusion terms are included in this display for M86.252. 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

Includes

Official

No Includes notes are included in this display for M86.252. 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 M86.252. 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 M86.252. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance
Clear documentation of subacute osteomyelitis
Specific identification of left femur involvement
Evidence of infection timeline spanning weeks to months
Clinical symptoms consistent with subacute bone infection

MEAT Support

HCC Buddy guidance
Clear documentation of subacute osteomyelitis
Specific identification of left femur involvement
Evidence of infection timeline spanning weeks to months
Clinical symptoms consistent with subacute bone infection

Audit Caution

HCC Buddy guidance
Confusing left versus right laterality
Misclassifying disease phase (subacute vs acute vs chronic)
Using when infection involves multiple bones
Failing to establish subacute timeline documentation

Common Mistakes

HCC Buddy guidance
M86.251 — Use for right femur involvement
M86.259 — Use when femur laterality is not documented
M86.052 — Use for acute hematogenous osteomyelitis of left femur
M86.652 — Use for chronic osteomyelitis of left femur

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 M86.252 an HCC code?

Yes. M86.252 (Subacute osteomyelitis, left femur) 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: M86.252 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
M86.252
Description
Subacute osteomyelitis, left femur
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 M86.252 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for M86.252

For M86.252, 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

M86.252 is the ICD-10-CM diagnosis code for subacute osteomyelitis, left femur. A bone infection in the left thighbone (femur) that develops gradually over weeks to months. M86.252 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, M86.252 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. 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 left-sided location is clearly documented in the medical record. For M86.252, 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 M86.252 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • Verify left-sided location is clearly documented in the medical record
  • Note any associated complications such as pathological fracture or sequestrum formation

Clinical Significance

Subacute osteomyelitis of the left femur is an intermediate-stage bone infection that develops gradually over weeks to months, potentially causing significant functional impairment and risk of progression to chronic infection. This condition affects the body's largest weight-bearing bone, making early intervention crucial to preserve mobility and prevent complications.

Documentation Requirements

  • Clear documentation of subacute osteomyelitis
  • Specific identification of left femur involvement
  • Evidence of infection timeline spanning weeks to months
  • Clinical symptoms consistent with subacute bone infection
  • Radiological confirmation of osteomyelitis in left femur
  • Laboratory findings supporting ongoing infectious process
  • Culture and sensitivity results when obtainable
  • Functional assessment including mobility and weight-bearing status

Commonly Confused Codes

  • M86.251: Use for right femur involvement
  • M86.259: Use when femur laterality is not documented
  • M86.052: Use for acute hematogenous osteomyelitis of left femur
  • M86.652: Use for chronic osteomyelitis of left femur

Child Codes

Code Hierarchy

Also searched as

  • M86 252
  • M86252

For M86.252, 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.

M86.252 maps to CMS-HCC V28 category 92, Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis. See the ICD-10 to HCC mapping hub for how the V28 crosswalk works. The mapping identifies a payment HCC category for M86.252. Review its source-labeled HCC coefficient above, check the RAF Calculator with complete member context for CMS-HCC V28 PY2026, and confirm the documentation the chart needs before the code is submitted. HCC Buddy shows no RAF score unless every required source and calculation check passes.

Work M86.252 in HCC Buddy

Open M86.252 in the Code Book for the full Index-to-Tabular path, MEAT checklist, and V28 HCC mapping, or in the Encoder to code from a keyword search. Pro includes 7 days to try everything, no card required.