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F09 ICD-10-CM Code: Unspecified mental disorder due to known physiological condition

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

Coding at a Glance

Tabular directives
5 inclusion terms · 2 Excludes1 · 1 code-first instruction

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 884 — ORGANIC DISTURBANCES AND INTELLECTUAL DISABILITY (MDC 19)
  • MS-DRG 974 — HIV WITH MAJOR RELATED CONDITION WITH MCC (MDC 25)
  • MS-DRG 975 — HIV WITH MAJOR RELATED CONDITION WITH CC (MDC 25)
  • MS-DRG 976 — HIV WITH MAJOR RELATED CONDITION WITHOUT CC/MCC (MDC 25)

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.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for F09 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

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Mental disorder NOS due to known physiological condition
  • Organic brain syndrome NOS
  • Organic mental disorder NOS
  • Organic psychosis NOS
  • Symptomatic psychosis NOS

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.

  • the underlying physiological condition

Coder workflow for F09

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

Before you code F09

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, F09 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).

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

  2. F09’s title joins a condition with an associated condition or complication. Confirm each component is documented. Where the classification presumes the link through the “with” convention, only a provider statement that the conditions are unrelated defeats it. A combination code is assigned only when it fully identifies the documented conditions; a required second code for the stage, type or manifestation is still reported when the notes ask for it (Guidelines I.B.9, I.A.15).

    Guide: Combination codes →

  3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with F09. 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 — F09 is appropriate when the documentation goes no further.
  2. Does the documentation support a condition named in F09’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.

    ReviewF06.7, F29

  3. Is the underlying (etiologic) condition the Code First note names documented?
    Yes → Sequence the underlying condition first, then F09.
    No → Continue; do not add an underlying condition the record does not document.

Consider F09. 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 associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).
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 F09(2 notes)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with F09: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareF06.7, F29

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

  • Code First — sequencing check(1 note)

    Coding workflow: Check whether the underlying or etiologic condition the note names is documented. When it is, sequence it before F09. Do not add an underlying condition the record does not document.

    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 subcategory for a sibling that names the missing detail.

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).

Documentation: Both the condition F09 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).

ReviewF06.7, F29

Documentation: Only one of the components this code’s title joins is documented.

Coding question: Is F09 supported?

Path: Review the code for the documented component on its own.

Reason: A combination code is assigned only when it fully identifies the documented conditions; otherwise the documented component takes its own code (Guidelines I.B.9).

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.

Coding context

The comparisons, hierarchy, index entries, guidelines, relationships, risk-adjustment and coverage context a coder commonly needs. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.

Don’t confuse F09 with…

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

The codes most likely to be picked instead of F09 — 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.

  • F06.7— 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 mild neurocognitive disorder due to known physiological condition moves the case to F06.7; the two are not reported together unless documented as unrelated.

    Full comparison: F09 vs F06.7 →

  • F29— 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 psychosis NOS moves the case to F29; the two are not reported together unless documented as unrelated.

    Full comparison: F09 vs F29 →

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.

Code Overview

Unspecified mental disorder due to known physiological condition is a billable ICD-10-CM diagnosis code (F09).

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

Indexed Clinical Terms (18)

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.

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 F09 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 2 Excludes1 notes: F29 — Unspecified psychosis not due to a substance or known physiological condition, F99 — Mental disorder, not otherwise specified.

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

Referenced by 2 Excludes2 notes: F63.1 — Pyromania, F63.2 — Kleptomania.

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

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 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 4 MS-DRGs: DRG 884 (MDC 19), DRG 974 (MDC 25), DRG 975 (MDC 25), DRG 976 (MDC 25).

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

Clinical classification (AHRQ CCSR):MBD013 — Miscellaneous mental and behavioral disorders/conditions (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 (Miscellaneous mental and behavioral disorders/conditions).

F06.8 — Other specified mental disorders due to known physiological condition, F07.9 — Unspecified personality and behavioral disorder due to known physiological condition, F48.8 — Other specified nonpsychotic mental disorders, F48.9 — Nonpsychotic mental disorder, unspecified, F52.0 — Hypoactive sexual desire disorder, F52.1 — Sexual aversion disorder, F52.21 — Male erectile disorder, F52.22 — Female sexual arousal disorder, F52.31 — Female orgasmic disorder, F52.32 — Male orgasmic disorder, F52.4 — Premature ejaculation, F52.5 — Vaginismus not due to a substance or known physiological condition, F52.6 — Dyspareunia not due to a substance or known physiological condition, F52.8 — Other sexual dysfunction not due to a substance or known physiological condition, F52.9 — Unspecified sexual dysfunction not due to a substance or known physiological condition, F54 — Psychological and behavioral factors associated with disorders or diseases classified elsewhere, F55.0 — Abuse of antacids, F55.1 — Abuse of herbal or folk remedies, F55.2 — Abuse of laxatives, F55.3 — Abuse of steroids or hormones, +32 more

Same Index main term, other category

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

E88.01 — Alpha-1-antitrypsin deficiency (alpha-1-antitrypsin), E88.02 — Plasminogen deficiency (plasminogen), E88.09 — Other disorders of plasma-protein metabolism, not elsewhere classified (pseudocholinesterase), E88.89 — Other specified metabolic disorders (dihydropyrimidine dehydrogenase), F01.50 — Vascular dementia, unspecified severity, without behavioral disturbance, psychotic disturbance, mood disturbance, and anxiety (multi-infarct), F03 — Unspecified dementia (presenile), F04 — Amnestic disorder due to known physiological condition (Korsakoff's, Korsakov's, Korsakow's), F05 — Delirium due to known physiological condition (infective), F06.2 — Psychotic disorder with delusions due to known physiological condition (schizophrenia-like, in epilepsy), F06.8 — Other specified mental disorders due to known physiological condition (epileptic), F10.14 — Alcohol abuse with alcohol-induced mood disorder (alcoholic, with, mood disorder, with, abuse), F10.150 — Alcohol abuse with alcohol-induced psychotic disorder with delusions (alcoholic, paranoid type, with, abuse), F10.151 — Alcohol abuse with alcohol-induced psychotic disorder with hallucinations (alcoholic, with, hallucinosis, with, abuse), F10.159 — Alcohol abuse with alcohol-induced psychotic disorder, unspecified (alcoholic, with, abuse), F10.180 — Alcohol abuse with alcohol-induced anxiety disorder (alcoholic, with, anxiety disorder, with, abuse), F10.231 — Alcohol dependence with withdrawal delirium (alcoholic, delirium tremens), F10.24 — Alcohol dependence with alcohol-induced mood disorder (alcoholic, with, mood disorder, with, dependence), F10.250 — Alcohol dependence with alcohol-induced psychotic disorder with delusions (alcoholic, paranoid type, with, dependence), F10.251 — Alcohol dependence with alcohol-induced psychotic disorder with hallucinations (alcoholic, with, hallucinosis, with, dependence), F10.259 — Alcohol dependence with alcohol-induced psychotic disorder, unspecified (alcoholic, with, dependence), +222 more

Contextual Map

Every relationship of F09 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 F09 with these 5 related codes in Claim Check

Hierarchy

Excludes1

Referenced by Excludes1 notes

Referenced by Excludes2 notes

  • F63.1 — Pyromania[Excludes2]: “mental disorders due to known physiological condition (F01-F09)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027
  • F63.2 — Kleptomania[Excludes2]: “stealing in mental disorders due to known physiological condition (F01-F09)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027

Clinical classification (CCSR)

MS-DRG Grouper

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 · FY2027
  • MDC 25 — Human Immunodeficiency Virus Infections[MDC crossing]: “Human Immunodeficiency Virus Infections — 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 · FY2027

Index entries (18)

  • Deficiency, deficient, cognitive[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Disease, diseased, mental, organic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Disorder (of), cognitive[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Disorder (of), cognitive, due togeneral medical condition (secondary to)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Disorder (of), mental (or behavioral) (nonpsychotic), due to (secondary to), brain disease, damage and dysfunction[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Disorder (of), mental (or behavioral) (nonpsychotic), due to (secondary to), general medical condition[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Disorder (of), mental (or behavioral) (nonpsychotic), organic or symptomatic[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Organic, brain syndrome[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • 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

Deep reference

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
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.

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 20, 2026 · All releases and sources

Labels on this page: Official source data · MedCoder structured relationship · MedCoder 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. "F09 — Unspecified mental disorder due to known physiological condition." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/f09-unspecified-mental-disorder-due-to-known-physiological-condition

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Unspecified mental disorder due to known physiological condition

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.