M16.5 ICD-10-CM Code: Unilateral post-traumatic osteoarthritis of hip

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for M16.5 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 M16.5 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for M16.5

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

Before you code M16.5

1. M16.5 is not reportable as written. Select the more specific code beneath it that the documentation supports. Codes are reported to the highest level of specificity the classification provides (Guidelines I.B.2).

   ReviewM16.50, M16.51, M16.52

   See the relationships section · Guide: How to choose an ICD-10-CM code →

Choose the right path

1. Does the documentation support one of the more specific codes beneath M16.5?
   Yes → Select that code and continue the checks below on its own page.
   No → M16.5 cannot be reported as written; query for the specificity its subcategory needs.

   ReviewM16.50, M16.51, M16.52

Consider M16.5. 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).

Official instructions as workflow

• Excludes2 — not part of M16.5(1 note)

  Coding workflow: The conditions named in this note are not included in M16.5. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareM47

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

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 M16.5 with…

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

The codes most likely to be picked instead of M16.5 — 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.

• M16.9— Specificity relationship (Review)

  Overlapping diagnoses in the same category.

  Overlapping codes in the same category — the documentation decides which is the more specific fit.

  What moves you there: A record that documents no more than “Osteoarthritis of hip, unspecified” takes M16.9; specificity in the record moves it back here.

  Full comparison: M16.5 vs M16.9 →

• M47— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of osteoarthritis of spine adds M47; it is not part of this code and both may be reported when both are documented.

  Full comparison: M16.5 vs M47 →

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

• Not billable as written — a more specific code is required: M16.50, M16.51, M16.52.

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 M16.5 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 4 Excludes1 notes: M12 — Other and unspecified arthropathy (via M16.-), M12.5 — Traumatic arthropathy, M13 — Other arthritis (via M16.-), M15 — Polyosteoarthritis (via M16.-).

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

Related Codes

Same Index main term, other category

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

M15.0 — Primary generalized (osteo)arthritis (generalized, primary), M15.1 — Heberden's nodes (with arthropathy) (interphalangeal, distal), M15.2 — Bouchard's nodes (with arthropathy) (interphalangeal, proximal), M15.3 — Secondary multiple arthritis (secondary, multiple), M15.4 — Erosive (osteo)arthritis (generalized, erosive), M15.8 — Other polyosteoarthritis (generalized, specified NEC), M15.9 — Polyosteoarthritis, unspecified (generalized), M17.0 — Bilateral primary osteoarthritis of knee (knee, bilateral), M17.1 — Unilateral primary osteoarthritis of knee (primary, knee), M17.2 — Bilateral post-traumatic osteoarthritis of knee (knee, bilateral, post-traumatic), M17.3 — Unilateral post-traumatic osteoarthritis of knee (post-traumatic NEC, knee), M17.4 — Other bilateral secondary osteoarthritis of knee (secondary, knee, bilateral), M17.5 — Other unilateral secondary osteoarthritis of knee (secondary, knee), M17.9 — Osteoarthritis of knee, unspecified (knee), M18.0 — Bilateral primary osteoarthritis of first carpometacarpal joints (primary, hand joint, first carpometacarpal joint, bilateral), M18.1 — Unilateral primary osteoarthritis of first carpometacarpal joint (primary, hand joint, first carpometacarpal joint), M18.2 — Bilateral post-traumatic osteoarthritis of first carpometacarpal joints (post-traumatic NEC, hand joint, first carpometacarpal joint, bilateral), M18.3 — Unilateral post-traumatic osteoarthritis of first carpometacarpal joint (post-traumatic NEC, hand joint, first carpometacarpal joint), M18.4 — Other bilateral secondary osteoarthritis of first carpometacarpal joints (secondary, hand joint, first carpometacarpal joint, bilateral), M18.5 — Other unilateral secondary osteoarthritis of first carpometacarpal joint (secondary, hand joint, first carpometacarpal joint), +23 more

Contextual Map

Every relationship of M16.5 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 M16.5 with these 4 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
• M00-M25 — Arthropathies[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M15-M19 — Osteoarthritis[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• M12 — Other and unspecified arthropathy[Excludes1](via M16.-): “arthrosis (M15-M19)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• M12.5 — Traumatic arthropathy[Excludes1]: “post-traumatic osteoarthritis of hip (M16.4-M16.5)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• M13 — Other arthritis[Excludes1](via M16.-): “arthrosis (M15-M19)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• M15 — Polyosteoarthritis[Excludes1](via M16.-): “bilateral involvement of single joint (M16-M19)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Nearest codes (18)

• M16 — Osteoarthritis of hip[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M16.0 — Bilateral primary osteoarthritis of hip[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M16.1 — Unilateral primary osteoarthritis of hip[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M16.10 — Unilateral primary osteoarthritis, unspecified hip[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M16.11 — Unilateral primary osteoarthritis, right hip[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M16.12 — Unilateral primary osteoarthritis, left hip[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M16.2 — Bilateral osteoarthritis resulting from hip dysplasia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• M16.3 — Unilateral osteoarthritis resulting from hip dysplasia[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 10 more

Change history

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

Common coding questions

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

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 M16.5 in its code family, with their registry titles.

• M16.3 — Unilateral osteoarthritis resulting from hip dysplasia
• M16.30 — Unilateral osteoarthritis resulting from hip dysplasia, unspecified hip
• M16.31 — Unilateral osteoarthritis resulting from hip dysplasia, right hip
• M16.32 — Unilateral osteoarthritis resulting from hip dysplasia, left hip
• M16.4 — Bilateral post-traumatic osteoarthritis of hip
• M16.50 — Unilateral post-traumatic osteoarthritis, unspecified hip
• M16.51 — Unilateral post-traumatic osteoarthritis, right hip
• M16.52 — Unilateral post-traumatic osteoarthritis, left hip
• M16.6 — Other bilateral secondary osteoarthritis of hip
• M16.7 — Other unilateral secondary osteoarthritis of hip

View all codes in the M16 family