M89.70 ICD-10-CM Code: Major osseous defect, unspecified site

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for M89.70 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 M89.70 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for M89.70

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

Before you code M89.70

1. Unspecified does not mean incorrect. When the record gives no greater specificity, M89.70 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).

   ReviewM89.71, M89.72, M89.73, M89.74, M89.75

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

2. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with M89.70. 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 — M89.70 is appropriate when the documentation goes no further.

   ReviewM89.71, M89.72, M89.73, M89.74, M89.75

2. Does the documentation support a condition named in M89.70’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.

   ReviewM96

3. Is the underlying (etiologic) condition the Code First note names documented?
   Yes → Sequence the underlying condition first, then M89.70.
   No → Continue; do not add an underlying condition the record does not document.

   ReviewM87, C40, M89.5, M86, M80, M81

Consider M89.70. 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).

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 M89.70(1 note)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with M89.70: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareM96

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

• Code First — sequencing check(8 notes)

  Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before M89.70. Do not add an underlying condition the record does not document.

  ReviewM87, C40, M89.5, M86, M80, M81

  See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

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.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

• Defect, defective, major osseous
• Defect, defective, osseous, major

Don’t confuse M89.70 with…

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

The codes most likely to be picked instead of M89.70 — 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.

• M96— 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 postprocedural osteopathies moves the case to M96; the two are not reported together unless documented as unrelated.

  Full comparison: M89.70 vs M96 →

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.

Verify Before Coding

• No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

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 M89.70 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 7 Use Additional Code instructions across 3 chapters: C40 — Malignant neoplasm of bone and articular cartilage of limbs (via M89.7.-), M80 — Osteoporosis with current pathological fracture (via M89.7.-), M81 — Osteoporosis without current pathological fracture (via M89.7.-), M86 — Osteomyelitis (via M89.7.-), M87 — Osteonecrosis (via M89.7.-), M89.5 — Osteolysis (via M89.7.-), T84.05 — Periprosthetic osteolysis of internal prosthetic joint (via M89.7.-).

These codes instruct coders to additionally report this code when it applies.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

FY2026 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.

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):MUS028 — Other specified bone disease and musculoskeletal deformities (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 category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Other specified bone disease and musculoskeletal deformities).

+700 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Defect, defective”; these codes share that main term but sit in a different category of the Tabular List.

K08.50 — Unsatisfactory restoration of tooth, unspecified (dental restoration), K08.59 — Other unsatisfactory restoration of tooth (dental restoration, specified NEC), M51.9 — Unspecified thoracic, thoracolumbar and lumbosacral intervertebral disc disorder (intervertebral annular fibrosis), M51.A0 — Intervertebral annulus fibrosus defect, lumbar region, unspecified size (intervertebral annular fibrosis, lumbar), M51.A1 — Intervertebral annulus fibrosus defect, small, lumbar region (intervertebral annular fibrosis, lumbar, small), M51.A2 — Intervertebral annulus fibrosus defect, large, lumbar region (intervertebral annular fibrosis, lumbar, large), M51.A3 — Intervertebral annulus fibrosus defect, lumbosacral region, unspecified size (intervertebral annular fibrosis, lumbosacral), M51.A4 — Intervertebral annulus fibrosus defect, small, lumbosacral region (intervertebral annular fibrosis, lumbosacral, small), M51.A5 — Intervertebral annulus fibrosus defect, large, lumbosacral region (intervertebral annular fibrosis, lumbosacral, large), M62.89 — Other specified disorders of muscle (extensor retinaculum), M95.8 — Other specified acquired deformities of musculoskeletal system (osteochondral NEC), O08.1 — Delayed or excessive hemorrhage following ectopic and molar pregnancy (coagulation, with, molar pregnancy), O67.0 — Intrapartum hemorrhage with coagulation defect (coagulation, intrapartum), O72.3 — Postpartum coagulation defects (coagulation, postpartum, with hemorrhage), O99.13 — Other diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism complicating the puerperium (coagulation, postpartum), P61.6 — Other transient neonatal disorders of coagulation (coagulation, newborn, transient), Q06.3 — Other congenital cauda equina malformations (developmental, cauda equina), Q13.89 — Other congenital malformations of anterior segment of eye (Descemet's membrane, congenital), Q20.1 — Double outlet right ventricle (Taussig-Bing), Q21.0 — Ventricular septal defect (Gerbode), +90 more

Contextual Map

Every relationship of M89.70 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 M89.70 with these 7 related codes 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 Use Additional Code instructions

• C40 — Malignant neoplasm of bone and articular cartilage of limbs[Use Additional Code](via M89.7.-): “code to identify major osseous defect, if applicable (M89.7-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• M80 — Osteoporosis with current pathological fracture[Use Additional Code](via M89.7.-): “code to identify major osseous defect, if applicable (M89.7-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• M81 — Osteoporosis without current pathological fracture[Use Additional Code](via M89.7.-): “major osseous defect, if applicable (M89.7-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• M86 — Osteomyelitis[Use Additional Code](via M89.7.-): “code to identify major osseous defect, if applicable (M89.7-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• M87 — Osteonecrosis[Use Additional Code](via M89.7.-): “code to identify major osseous defect, if applicable (M89.7-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• M89.5 — Osteolysis[Use Additional Code](via M89.7.-): “code to identify major osseous defect, if applicable (M89.7-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T84.05 — Periprosthetic osteolysis of internal prosthetic joint[Use Additional Code](via M89.7.-): “code to identify major osseous defect, if applicable (M89.7-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• MUS028 — Other specified bone disease and musculoskeletal deformities[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• 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) · FY2026
• 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) · 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

Index entries

• Defect, defective, major osseous[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Defect, defective, osseous, major[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (40)

• M89 — Other disorders of bone[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M89.639 — Osteopathy after poliomyelitis, unspecified forearm[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M89.64 — Osteopathy after poliomyelitis, hand[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M89.641 — Osteopathy after poliomyelitis, right hand[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M89.642 — Osteopathy after poliomyelitis, left hand[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M89.649 — Osteopathy after poliomyelitis, unspecified hand[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M89.65 — Osteopathy after poliomyelitis, thigh[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M89.651 — Osteopathy after poliomyelitis, right thigh[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

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to M89.70 in its code family, with their registry titles.

• M89.672 — Osteopathy after poliomyelitis, left ankle and foot
• M89.679 — Osteopathy after poliomyelitis, unspecified ankle and foot
• M89.68 — Osteopathy after poliomyelitis, other site
• M89.69 — Osteopathy after poliomyelitis, multiple sites
• M89.7 — Major osseous defect
• M89.71 — Major osseous defect, shoulder region
• M89.711 — Major osseous defect, right shoulder region
• M89.712 — Major osseous defect, left shoulder region
• M89.719 — Major osseous defect, unspecified shoulder region
• M89.72 — Major osseous defect, humerus

View all codes in the M89 family