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M90.549 ICD-10-CM Code: Osteonecrosis in diseases classified elsewhere, unspecified hand

Compare with another codeCheck this code on a claim

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
10 Excludes1 · 3 code-first instructions
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 39 · RxHCC V08 category 80

Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.

What you need to know

Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.

Code firstSequence the underlying condition before this code
  • underlying disease, such as:
  • caisson disease (T70.3)
  • hemoglobinopathy (D50-D64)
Excludes1Never report with this code
  • osteochondritis, osteomyelitis, and osteopathy (in):
  • cryptococcosis (B45.3)
  • diabetes mellitus (E08-E13 with .69-)
  • gonococcal (A54.43)

+6 more in Instructions

Most relevant related codes MedCoder-derived

Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.

CompareCheck ClaimView Related Codes

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 v44, Appendix B.

  • MS-DRG 553 — BONE DISEASES AND ARTHROPATHIES WITH MCC (MDC 08)
  • MS-DRG 554 — BONE DISEASES AND ARTHROPATHIES WITHOUT 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 · RxHCC V08 HCC 80

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 M90.549 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on M90.549 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).

Code First

Underlying conditions that must be sequenced before this code.

  • underlying disease, such as:
  • caisson disease (T70.3)
  • hemoglobinopathy (D50-D64)

Source: inherited from M90.5

Coder workflow for M90.549

MedCoder structured workflow — derived from this code’s own official record

Before you code M90.549

  1. M90.549 is a manifestation code (“in diseases classified elsewhere”). Confirm the underlying condition is documented and sequence it first; a manifestation code is not reported as the first-listed or principal diagnosis. The etiology/manifestation convention (Guidelines I.A.13).

    See the official tabular notes · Guide: Manifestation codes and Code First sequencing →

  2. Unspecified does not mean incorrect. When the record gives no greater specificity, M90.549 may be the appropriate code. Check the record for detail that supports a more specific sibling. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    ReviewM90.541, M90.542

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  3. Laterality is coded in this family. Confirm the side documented — right, left, or bilateral — and select the matching code (this page’s code: unspecified). 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).

    ReviewM90.541 · right, M90.542 · left

    Guide: Laterality coding →

  4. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with M90.549. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — M90.549 is appropriate when the documentation goes no further.

    ReviewM90.541, M90.542

  2. Does the documentation support a condition named in M90.549’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.

    ReviewB45.3, A54.43, A52.11, N25.0, A02.24, A51.46

  3. Is the underlying (etiologic) condition the Code First note names documented?
    Yes → Sequence the underlying condition first, then M90.549.
    No → A manifestation code needs its underlying condition — query before reporting it.

    ReviewT70.3

  4. 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.

    ReviewM90.541 · right, M90.542 · left

Consider M90.549. Then 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).
The underlying (etiologic) condition
Named in the Code First note; sequenced before this code when documented (Guidelines I.A.13).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes1 — check before selecting M90.549(10 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with M90.549: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareB45.3, A54.43, A52.11, N25.0, A02.24, A51.46

    See the official tabular notes · Guidelines I.A.12.a

  • Code First — sequencing check(3 notes)

    Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before M90.549. Do not add an underlying condition the record does not document.

    ReviewT70.3

    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: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the specific siblings in this subcategory and what each requires the record to state.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

ReviewM90.541, M90.542

Documentation: Both the condition M90.549 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).

ReviewB45.3, A54.43, A52.11, N25.0, A02.24, A51.46

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).

ReviewM90.541 · right, M90.542 · left

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.

Don’t confuse M90.549 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of M90.549 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • B45.3— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of cryptococcosis moves the case to B45.3; the two are not reported together unless documented as unrelated.

    Full comparison: M90.549 vs B45.3 →

  • E08— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of diabetes mellitus moves the case to E08; the two are not reported together unless documented as unrelated.

    Full comparison: M90.549 vs E08 →

  • E13— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of diabetes mellitus moves the case to E13; the two are not reported together unless documented as unrelated.

    Full comparison: M90.549 vs E13 →

  • A54.43— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of gonococcal moves the case to A54.43; the two are not reported together unless documented as unrelated.

    Full comparison: M90.549 vs A54.43 →

  • A52.11— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of neurogenic syphilis moves the case to A52.11; the two are not reported together unless documented as unrelated.

    Full comparison: M90.549 vs A52.11 →

  • N25.0— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of renal osteodystrophy moves the case to N25.0; the two are not reported together unless documented as unrelated.

    Full comparison: M90.549 vs N25.0 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Coding context

Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Code Overview

Osteonecrosis in diseases classified elsewhere, unspecified hand is a billable ICD-10-CM diagnosis code (M90.549).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Verify Before Coding

  • Principal-diagnosis restriction. This is a manifestation code: the Medicare Code Editor requires the underlying condition (etiology) to be sequenced first, with this code reported after it.
  • CC as a secondary diagnosis (FY2027). 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-derived relationships — computed from published CMS and AHRQ datasets

Other codes that name M90.549 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 Excludes1 note: M87 — Osteonecrosis (via M90.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 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 217 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 2 MS-DRGs: DRG 553 (MDC 08), DRG 554 (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):MUS030 — Aseptic necrosis and osteonecrosis.

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.

M87.852 — Other osteonecrosis, left femur, M87.859 — Other osteonecrosis, unspecified femur, M87.861 — Other osteonecrosis, right tibia, M87.862 — Other osteonecrosis, left tibia, M87.863 — Other osteonecrosis, unspecified tibia, M87.864 — Other osteonecrosis, right fibula, M87.865 — Other osteonecrosis, left fibula, M87.869 — Other osteonecrosis, unspecified fibula, M87.871 — Other osteonecrosis, right ankle, M87.872 — Other osteonecrosis, left ankle, M87.873 — Other osteonecrosis, unspecified ankle, M87.874 — Other osteonecrosis, right foot, M87.875 — Other osteonecrosis, left foot, M87.876 — Other osteonecrosis, unspecified foot, M87.877 — Other osteonecrosis, right toe(s), M87.878 — Other osteonecrosis, left toe(s), M87.879 — Other osteonecrosis, unspecified toe(s), M87.88 — Other osteonecrosis, other site, M87.89 — Other osteonecrosis, multiple sites, M87.9 — Osteonecrosis, unspecified, +197 more

Principal diagnosis restriction (Medicare Code Editor)

Manifestation code — the underlying condition is sequenced first.

Same condition, opposite side

Same category and title, differing only in which side of the body is affected.

M90.541 — Osteonecrosis in diseases classified elsewhere, right hand (right)Compare M90.549 vs M90.541 →, M90.542 — Osteonecrosis in diseases classified elsewhere, left hand (left)Compare M90.549 vs M90.542 →

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.

M90.512 — Osteonecrosis in diseases classified elsewhere, left shoulder, M90.519 — Osteonecrosis in diseases classified elsewhere, unspecified shoulder, M90.521 — Osteonecrosis in diseases classified elsewhere, right upper arm, M90.522 — Osteonecrosis in diseases classified elsewhere, left upper arm, M90.529 — Osteonecrosis in diseases classified elsewhere, unspecified upper arm, M90.531 — Osteonecrosis in diseases classified elsewhere, right forearm, M90.532 — Osteonecrosis in diseases classified elsewhere, left forearm, M90.539 — Osteonecrosis in diseases classified elsewhere, unspecified forearm, M90.541 — Osteonecrosis in diseases classified elsewhere, right hand, M90.542 — Osteonecrosis in diseases classified elsewhere, left hand, M90.551 — Osteonecrosis in diseases classified elsewhere, right thigh, M90.552 — Osteonecrosis in diseases classified elsewhere, left thigh, M90.559 — Osteonecrosis in diseases classified elsewhere, unspecified thigh, M90.561 — Osteonecrosis in diseases classified elsewhere, right lower leg, M90.562 — Osteonecrosis in diseases classified elsewhere, left lower leg, M90.569 — Osteonecrosis in diseases classified elsewhere, unspecified lower leg, M90.571 — Osteonecrosis in diseases classified elsewhere, right ankle and foot, M90.572 — Osteonecrosis in diseases classified elsewhere, left ankle and foot, M90.579 — Osteonecrosis in diseases classified elsewhere, unspecified ankle and foot, M90.58 — Osteonecrosis in diseases classified elsewhere, other site, +588 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Aseptic necrosis and osteonecrosis).

M90.512 — Osteonecrosis in diseases classified elsewhere, left shoulder, M90.519 — Osteonecrosis in diseases classified elsewhere, unspecified shoulder, M90.521 — Osteonecrosis in diseases classified elsewhere, right upper arm, M90.522 — Osteonecrosis in diseases classified elsewhere, left upper arm, M90.529 — Osteonecrosis in diseases classified elsewhere, unspecified upper arm, M90.531 — Osteonecrosis in diseases classified elsewhere, right forearm, M90.532 — Osteonecrosis in diseases classified elsewhere, left forearm, M90.539 — Osteonecrosis in diseases classified elsewhere, unspecified forearm, M90.541 — Osteonecrosis in diseases classified elsewhere, right hand, M90.542 — Osteonecrosis in diseases classified elsewhere, left hand, M90.551 — Osteonecrosis in diseases classified elsewhere, right thigh, M90.552 — Osteonecrosis in diseases classified elsewhere, left thigh, M90.559 — Osteonecrosis in diseases classified elsewhere, unspecified thigh, M90.561 — Osteonecrosis in diseases classified elsewhere, right lower leg, M90.562 — Osteonecrosis in diseases classified elsewhere, left lower leg, M90.569 — Osteonecrosis in diseases classified elsewhere, unspecified lower leg, M90.571 — Osteonecrosis in diseases classified elsewhere, right ankle and foot, M90.572 — Osteonecrosis in diseases classified elsewhere, left ankle and foot, M90.579 — Osteonecrosis in diseases classified elsewhere, unspecified ankle and foot, M90.58 — Osteonecrosis in diseases classified elsewhere, other site, +258 more

Contextual Map

Every relationship of M90.549 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 M90.549 with this related code in Claim Check

Hierarchy

Referenced by Excludes1 notes

  • M87 — Osteonecrosis[Excludes1](via M90.-): “osteochondropathies (M90-M93)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027

Clinical classification (CCSR)

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) · FY2027
  • DRG 553 — BONE DISEASES AND ARTHROPATHIES WITH MCC[MS-DRG]: “BONE DISEASES AND ARTHROPATHIES WITH MCC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
  • DRG 554 — BONE DISEASES AND ARTHROPATHIES WITHOUT MCC[MS-DRG]: “BONE DISEASES AND ARTHROPATHIES WITHOUT MCC (MDC 08)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027

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. 18,439 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Nearest codes (40)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Relevant guides

Reference

Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.

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 FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 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 — v44 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-derived 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 editorial 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.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules

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. "M90.549 — Osteonecrosis in diseases classified elsewhere, unspecified hand." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/m90.549-osteonecrosis-in-diseases-classified-elsewhere-unspecified-hand

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Osteonecrosis in diseases classified elsewhere, unspecified hand

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, 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 M90.549 in its code family, with their registry titles.

View all codes in the M90 family