F42.9 ICD-10-CM Code: Obsessive-compulsive disorder, unspecified

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for F42.9 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 F42.9 itself; “inherited from” names the category or block whose note applies here.

Coder workflow for F42.9

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

Before you code F42.9

1. Unspecified does not mean incorrect. When the record gives no greater specificity, F42.9 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).

   ReviewF42.2, F42.3, F42.4, F42.8

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

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 — F42.9 is appropriate when the documentation goes no further.

   ReviewF42.2, F42.3, F42.4, F42.8

Consider F42.9. 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).

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

• Excludes2 — not part of F42.9(3 notes)

  Coding workflow: The conditions named in this note are not included in F42.9. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareF60.5, F32, F33, F20

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

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 (1)

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.

• Disorder (of), obsessive-compulsive

Don’t confuse F42.9 with…

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

The codes most likely to be picked instead of F42.9 — 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.

• F60.5— 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 obsessive-compulsive personality (disorder) adds F60.5; it is not part of this code and both may be reported when both are documented.

  Full comparison: F42.9 vs F60.5 →

• F32— 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 obsessive-compulsive symptoms occurring in depression adds F32; it is not part of this code and both may be reported when both are documented.

  Full comparison: F42.9 vs F32 →

• F33— 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 obsessive-compulsive symptoms occurring in depression adds F33; it is not part of this code and both may be reported when both are documented.

  Full comparison: F42.9 vs F33 →

• F20— 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 obsessive-compulsive symptoms occurring in schizophrenia adds F20; it is not part of this code and both may be reported when both are documented.

  Full comparison: F42.9 vs F20 →

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 F42.9 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: R46.81 — Obsessive-compulsive behavior (via F42.-).

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

Referenced by 4 Excludes2 notes: F60.5 — Obsessive-compulsive personality disorder (via F42.-), F93.0 — Separation anxiety disorder of childhood (via F42.-), F98 — Other behavioral and emotional disorders with onset usually occurring in childhood and adolescence (via F42.-), F98.4 — Stereotyped movement disorders (via F42.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

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 1 MS-DRG: DRG 882 (MDC 19).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):MBD006 — Obsessive-compulsive and related disorders (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 (Obsessive-compulsive and related disorders).

F42 — Obsessive-compulsive disorder, F42.2 — Mixed obsessional thoughts and acts, F42.3 — Hoarding disorder, F42.4 — Excoriation (skin-picking) disorder, F42.8 — Other obsessive-compulsive disorder, F45.22 — Body dysmorphic disorder, F63.3 — Trichotillomania

Contextual Map

Every relationship of F42.9 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 F42.9 with these 5 related codes in Claim Check

Hierarchy

• F01-F99 — Chapter 5: Mental, Behavioral and Neurodevelopmental Disorders (F01-F99) (F01-F99)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• F40-F48 — Anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• R46.81 — Obsessive-compulsive behavior[Excludes1](via F42.-): “obsessive-compulsive disorder (F42.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes

• F60.5 — Obsessive-compulsive personality disorder[Excludes2](via F42.-): “obsessive-compulsive disorder (F42.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F93.0 — Separation anxiety disorder of childhood[Excludes2](via F42.-): “nonpsychotic mental disorders (F40-F48)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F98 — Other behavioral and emotional disorders with onset usually occurring in childhood and adolescence[Excludes2](via F42.-): “obsessive-compulsive disorder (F42.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• F98.4 — Stereotyped movement disorders[Excludes2](via F42.-): “compulsions in obsessive-compulsive disorder (F42.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• MBD006 — Obsessive-compulsive and related disorders[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• DRG 882 — NEUROSES EXCEPT DEPRESSIVE[MS-DRG]: “NEUROSES EXCEPT DEPRESSIVE (MDC 19)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 19 — Mental Diseases and Disorders[MDC crossing]: “Mental Diseases and Disorders — 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.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Disorder (of), obsessive-compulsive[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes

• F42 — Obsessive-compulsive disorder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• F42.2 — Mixed obsessional thoughts and acts[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• F42.3 — Hoarding disorder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• F42.4 — Excoriation (skin-picking) disorder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• F42.8 — Other obsessive-compulsive disorder[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Change history

• FY2017 — Added to the code set[Change history]— CMS release files (code change ledger) · icd10cm-fy2017

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 F42.9 in its code family, with their registry titles.

• F42 — Obsessive-compulsive disorder
• F42.2 — Mixed obsessional thoughts and acts
• F42.3 — Hoarding disorder
• F42.4 — Excoriation (skin-picking) disorder
• F42.8 — Other obsessive-compulsive disorder

View all codes in the F42 family