M86.021 ICD-10-CM Code: Acute hematogenous osteomyelitis, right humerus
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Coding at a Glance
- Tabular directives
- 5 Excludes1 · 4 Excludes2 · 2 use-additional codes
- Risk adjustment
- CMS-HCC V28: 1 category · CMS-HCC V22 category 39
Inpatient Payment Groups (MS-DRG)
Potential MS-DRG participation — not a DRG assignment.
MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.
- MS-DRG 539 — OSTEOMYELITIS WITH MCC (MDC 08)
- MS-DRG 540 — OSTEOMYELITIS WITH CC (MDC 08)
- MS-DRG 541 — OSTEOMYELITIS WITHOUT CC/MCC (MDC 08)
A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.
Risk Adjustment (CMS-HCC)
Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.
- HCC 92 — Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis
Other models: CMS-HCC V22 HCC 39
Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.
Coding instructions
Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for M86.021 in the official ICD-10-CM tabular list, quoted as published.
Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2026Effective: October 1, 2025
Notes without a marker are published on M86.021 itself; “inherited from” names the category or block whose note applies here.
Excludes1 — Not Coded Here
Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
- osteomyelitis due to:
- echinococcus (B67.2) inherited from M86Compare M86.021 vs B67.2 →
- gonococcus (A54.43) inherited from M86Compare M86.021 vs A54.43 →
- salmonella (A02.24) inherited from M86Compare M86.021 vs A02.24 →
- postprocedural osteopathies (M96.-) inherited from M86-M90Compare M86.021 vs M96 →
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- ostemyelitis of:
- orbit (H05.0-) Compare M86.021 vs H05.0 →
- petrous bone (H70.2-) Compare M86.021 vs H70.2 →
- vertebra (M46.2-) Compare M86.021 vs M46.2 →
Source: inherited from M86
Coder workflow for M86.021
MedCoder structured workflow — derived from this code’s own official record
Before you code M86.021
- Laterality is coded in this family. Confirm the side documented — right, left, or bilateral — and select the matching code (this page’s code: right). The unspecified-side code applies only when the record states no side. Laterality is assigned from the documented side; where a bilateral code exists and both sides are documented, it is used instead of two unilateral codes (Guidelines I.B.13).
- Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with M86.021. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).
Choose the right path
- Does the documentation support a condition named in M86.021’s Excludes1 note?
Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
No → Continue. - Is the side documented?
Yes → Select the code for the documented side (or the bilateral code when both sides are documented and one exists).
No → Use the unspecified-side code only when the record states no side; a query is the alternative.
Consider M86.021. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.
Documentation check
- The provider’s diagnostic statement
- Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
- Laterality
- Right, left or bilateral as documented; unspecified only when the record states no side (Guidelines I.B.13).
- Acuity
- Acute or chronic as documented; when both are documented and separate codes exist, both are reported with the acute code first (Guidelines I.B.8).
- The conditions the Use Additional Code note names
- Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.
Official instructions as workflow
Excludes1 — check before selecting M86.021(5 notes)
Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with M86.021: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.
CompareB67.2, A54.43, A02.24, M96
See the official tabular notes · Guidelines I.A.12.a
Excludes2 — not part of M86.021(4 notes)
Coding workflow: The conditions named in this note are not included in M86.021. When the record documents both, both may be reported; the note is a boundary, not a prohibition.
See the official tabular notes · Guidelines I.A.12.b
Use Additional Code — after identifying M86.021(2 notes)
Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with M86.021 when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.
ReviewM89.7
See the official tabular notes · Guidelines I.A.13
Coding decision scenarios
Pattern scenarios for this code’s structure — decision rules, not clinical cases
Documentation: Both the condition M86.021 describes and a condition named in its Excludes1 note are documented for the same encounter.
Coding question: Can both codes be reported?
Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.
Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).
Documentation: The record documents the condition on one side only.
Coding question: Which code in this family applies?
Path: Select the sibling code for the documented side.
Reason: Laterality is assigned from the documented side; the unspecified-side code is for records that state no side (Guidelines I.B.13).
Documentation: A condition the Use Additional Code note names is documented.
Coding question: Is a second code reported with M86.021?
Path: Review the Use Additional Code note and the code it names.
Reason: The additional code is reported when the record documents the condition; a conditional instruction applies only when its condition is met (Guidelines I.A.13).
ReviewM89.7
Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.
Code Overview
MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.
Decision Points
The directives on this code's own record, as a pre-claim checklist.
- Laterality is coded in this family. Confirm the documented side matches the code — the opposite-side siblings are in the relationships section. See the opposite-side sibling codes
- 2 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
- 5 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
- 4 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes
Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.
Verify Before Coding
- CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.
Relationships & Classification
MedCoder structured relationships — computed from published CMS and AHRQ datasets
Other codes that name M86.021 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.
Referenced by 1 Code First instruction: M89.7 — Major osseous defect (via M86.-).
Each of these codes carries a Code First note naming this condition — when that code is reported, THIS code is sequenced first, ahead of it.
MS-DRG Grouper Relationships (FY2026)
Potential MS-DRG participation — not a DRG assignment.
FY2026 MS-DRG: CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 64 clinically related codes on its CMS exclusion list.
Named in the grouper logic of 3 MS-DRGs: DRG 539 (MDC 08), DRG 540 (MDC 08), DRG 541 (MDC 08).
From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.
Clinical classification (AHRQ CCSR):MUS002 — Osteomyelitis (default).
Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.
Related Codes
Same clinical process (MS-DRG)
Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.
M46.31 — Infection of intervertebral disc (pyogenic), occipito-atlanto-axial region, M46.32 — Infection of intervertebral disc (pyogenic), cervical region, M46.33 — Infection of intervertebral disc (pyogenic), cervicothoracic region, M46.34 — Infection of intervertebral disc (pyogenic), thoracic region, M46.35 — Infection of intervertebral disc (pyogenic), thoracolumbar region, M46.36 — Infection of intervertebral disc (pyogenic), lumbar region, M46.37 — Infection of intervertebral disc (pyogenic), lumbosacral region, M46.38 — Infection of intervertebral disc (pyogenic), sacral and sacrococcygeal region, M46.39 — Infection of intervertebral disc (pyogenic), multiple sites in spine, M86.00 — Acute hematogenous osteomyelitis, unspecified site, M86.08 — Acute hematogenous osteomyelitis, other sites, M86.09 — Acute hematogenous osteomyelitis, multiple sites, M86.10 — Other acute osteomyelitis, unspecified site, M86.18 — Other acute osteomyelitis, other site, M86.19 — Other acute osteomyelitis, multiple sites, M86.20 — Subacute osteomyelitis, unspecified site, M86.28 — Subacute osteomyelitis, other site, M86.29 — Subacute osteomyelitis, multiple sites, M86.30 — Chronic multifocal osteomyelitis, unspecified site, M86.321 — Chronic multifocal osteomyelitis, right humerus, +43 more
Same condition, opposite side
Same category and title, differing only in which side of the body is affected.
M86.022 — Acute hematogenous osteomyelitis, left humerus (left)Compare M86.021 vs M86.022 →, M86.029 — Acute hematogenous osteomyelitis, unspecified humerus (unspecified)Compare M86.021 vs M86.029 →
Same CMS-HCC risk category (V28)
CMS maps these diagnoses to the same Hierarchical Condition Category (Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis) for risk-adjusted payment.
M46.35 — Infection of intervertebral disc (pyogenic), thoracolumbar region, M46.36 — Infection of intervertebral disc (pyogenic), lumbar region, M46.37 — Infection of intervertebral disc (pyogenic), lumbosacral region, M46.38 — Infection of intervertebral disc (pyogenic), sacral and sacrococcygeal region, M46.39 — Infection of intervertebral disc (pyogenic), multiple sites in spine, M72.6 — Necrotizing fasciitis, M86.00 — Acute hematogenous osteomyelitis, unspecified site, M86.011 — Acute hematogenous osteomyelitis, right shoulder, M86.012 — Acute hematogenous osteomyelitis, left shoulder, M86.019 — Acute hematogenous osteomyelitis, unspecified shoulder, M86.022 — Acute hematogenous osteomyelitis, left humerus, M86.029 — Acute hematogenous osteomyelitis, unspecified humerus, M86.031 — Acute hematogenous osteomyelitis, right radius and ulna, M86.032 — Acute hematogenous osteomyelitis, left radius and ulna, M86.039 — Acute hematogenous osteomyelitis, unspecified radius and ulna, M86.041 — Acute hematogenous osteomyelitis, right hand, M86.042 — Acute hematogenous osteomyelitis, left hand, M86.049 — Acute hematogenous osteomyelitis, unspecified hand, M86.051 — Acute hematogenous osteomyelitis, right femur, M86.052 — Acute hematogenous osteomyelitis, left femur, +588 more
Same clinical category (CCSR)
AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Osteomyelitis).
M46.23 — Osteomyelitis of vertebra, cervicothoracic region, M46.24 — Osteomyelitis of vertebra, thoracic region, M46.25 — Osteomyelitis of vertebra, thoracolumbar region, M46.26 — Osteomyelitis of vertebra, lumbar region, M46.27 — Osteomyelitis of vertebra, lumbosacral region, M46.28 — Osteomyelitis of vertebra, sacral and sacrococcygeal region, M86.00 — Acute hematogenous osteomyelitis, unspecified site, M86.011 — Acute hematogenous osteomyelitis, right shoulder, M86.012 — Acute hematogenous osteomyelitis, left shoulder, M86.019 — Acute hematogenous osteomyelitis, unspecified shoulder, M86.022 — Acute hematogenous osteomyelitis, left humerus, M86.029 — Acute hematogenous osteomyelitis, unspecified humerus, M86.031 — Acute hematogenous osteomyelitis, right radius and ulna, M86.032 — Acute hematogenous osteomyelitis, left radius and ulna, M86.039 — Acute hematogenous osteomyelitis, unspecified radius and ulna, M86.041 — Acute hematogenous osteomyelitis, right hand, M86.042 — Acute hematogenous osteomyelitis, left hand, M86.049 — Acute hematogenous osteomyelitis, unspecified hand, M86.051 — Acute hematogenous osteomyelitis, right femur, M86.052 — Acute hematogenous osteomyelitis, left femur, +174 more
Same Index main term, other category
The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Osteomyelitis”; these codes share that main term but sit in a different category of the Tabular List.
A01.05 — Typhoid osteomyelitis (typhoid), A02.24 — Salmonella osteomyelitis (Salmonella), A50.02 — Early congenital syphilitic osteochondropathy (syphilitic, congenital), A52.77 — Syphilis of bone and joint (syphilitic), B67.2 — Echinococcus granulosus infection of bone (echinococcal), H05.02 — Osteomyelitis of orbit (orbit), M27.2 — Inflammatory conditions of jaws (jaw), M46.20 — Osteomyelitis of vertebra, site unspecified (vertebra), M46.21 — Osteomyelitis of vertebra, occipito-atlanto-axial region (vertebra, occipito-atlanto-axial region), M46.22 — Osteomyelitis of vertebra, cervical region (vertebra, cervical region), M46.23 — Osteomyelitis of vertebra, cervicothoracic region (vertebra, cervicothoracic region), M46.24 — Osteomyelitis of vertebra, thoracic region (vertebra, thoracic region), M46.25 — Osteomyelitis of vertebra, thoracolumbar region (vertebra, thoracolumbar region), M46.26 — Osteomyelitis of vertebra, lumbar region (vertebra, lumbar region), M46.27 — Osteomyelitis of vertebra, lumbosacral region (vertebra, lumbosacral region), M46.28 — Osteomyelitis of vertebra, sacral and sacrococcygeal region (vertebra, sacrococcygeal region)
Contextual Map
Every relationship of M86.021 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.
Run M86.021 with this related code in Claim Check
Hierarchy
- M00-M99 — Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue (M00-M99) (M00-M99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- M86-M90 — Other osteopathies[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
Referenced by Code First instructions
- M89.7 — Major osseous defect[Code First](via M86.-): “osteomyelitis (M86.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
Clinical classification (CCSR)
- MUS002 — Osteomyelitis[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
Risk adjustment (CMS-HCC)
- HCC 92 — Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis [CMS-HCC]— CMS-HCC V28 · 2026
MS-DRG Grouper
- CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
- DRG 539 — OSTEOMYELITIS WITH MCC[MS-DRG]: “OSTEOMYELITIS WITH MCC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
- DRG 540 — OSTEOMYELITIS WITH CC[MS-DRG]: “OSTEOMYELITIS WITH CC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
- DRG 541 — OSTEOMYELITIS WITHOUT CC/MCC[MS-DRG]: “OSTEOMYELITIS WITHOUT CC/MCC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
MDC crossing
- MDC 08 — Diseases and Disorders of the Musculoskeletal System and Connective Tissue[MDC crossing]: “Diseases and Disorders of the Musculoskeletal System and Connective Tissue — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 18,508 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026
Nearest codes (40)
- M86 — Osteomyelitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- M86.0 — Acute hematogenous osteomyelitis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- M86.00 — Acute hematogenous osteomyelitis, unspecified site[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- M86.01 — Acute hematogenous osteomyelitis, shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- M86.011 — Acute hematogenous osteomyelitis, right shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- M86.012 — Acute hematogenous osteomyelitis, left shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- M86.019 — Acute hematogenous osteomyelitis, unspecified shoulder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- M86.02 — Acute hematogenous osteomyelitis, humerus[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
- and 32 more
Change history
- FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016
Sources for this page
Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.
- Code, title, tabular notes and index terms Official source data
- CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
- Claim edits Official source data
- CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
- Inpatient payment groups Official source data
- CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
- Risk adjustment Official source data
- 2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
- Change history and date-of-service validity Official source data
- CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
- Comparisons, relationships and the contextual map MedCoder structured relationship
- Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
- Summary and FAQ answers MedCoder explanation
- Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.
Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates
Cite this page
Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.
MedCoder.ai. "M86.021 — Acute hematogenous osteomyelitis, right humerus." ICD-10-CM FY2026. https://medcoder.ai/icd10/code/m86.021-acute-hematogenous-osteomyelitis-right-humerus
Change history
- FY2016 — October 1, 2015In the code set at ICD-10-CM adoptionAcute hematogenous osteomyelitis, right humerus
No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.
Nearest Codes in This Family
Official ICD-10-CM classifications closest to M86.021 in its code family, with their registry titles.
- M86.01 — Acute hematogenous osteomyelitis, shoulder
- M86.011 — Acute hematogenous osteomyelitis, right shoulder
- M86.012 — Acute hematogenous osteomyelitis, left shoulder
- M86.019 — Acute hematogenous osteomyelitis, unspecified shoulder
- M86.02 — Acute hematogenous osteomyelitis, humerus
- M86.022 — Acute hematogenous osteomyelitis, left humerus
- M86.029 — Acute hematogenous osteomyelitis, unspecified humerus
- M86.03 — Acute hematogenous osteomyelitis, radius and ulna
- M86.031 — Acute hematogenous osteomyelitis, right radius and ulna
- M86.032 — Acute hematogenous osteomyelitis, left radius and ulna