Mental health diagnoses are coded from Chapter 5 of ICD-10-CM, codes F01 to F99, with the most common outpatient codes being depression (F32 and F33), anxiety (F41), trauma and adjustment disorders (F43) and ADHD (F90), while Z55 to Z65 codes add social risk factors as secondary diagnoses. Sleep problems treated in their own right are coded separately; see our insomnia ICD-10 guide.
Every therapy or psychiatry claim needs a diagnosis that supports medical necessity for the CPT code billed. A vague or mismatched code is one of the quickest ways to get a session denied, even when the clinical work was flawless.
This guide lists the ICD-10-CM codes behavioral health practices use most, validated against the FY2027 code set that took effect on October 1, 2026. It also explains specificity rules, when Z codes help or hurt, and why the name in DSM-5-TR does not always match the ICD-10-CM title on the claim. For the procedure side, see our mental health CPT codes reference; for the full billing cycle, see our mental health billing guide.
Key Takeaways
- Use the ICD-10-CM code set in effect on the date of service. FY2027 runs from October 1, 2026 to September 30, 2027.
- FY2027 made only one change to the mental health chapter: new code F64.A, Gender identity disorder, in remission.
- Code to the highest specificity documented: episode (single or recurrent), severity and remission status for depression, and type for ADHD and PTSD.
- Outpatient claims never code rule-out or probable diagnoses. Code the symptoms, such as R45.851 for suicidal ideations, until the diagnosis is confirmed.
- SDOH Z codes (Z55 to Z65) can come from any care team member’s documentation or a patient’s self-report, but they are rarely accepted as the only diagnosis for psychotherapy.
How Chapter 5 (F01-F99) Is Organized
| Block | ICD-10-CM title | Common examples |
|---|---|---|
| F01-F09 | Mental disorders due to known physiological conditions | Dementia and delirium codes |
| F10-F19 | Mental and behavioral disorders due to psychoactive substance use | Alcohol, opioid, cannabis use disorders |
| F20-F29 | Schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders | Schizophrenia, schizoaffective disorder |
| F30-F39 | Mood [affective] disorders | Depression, bipolar, dysthymia |
| F40-F48 | Anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders | GAD, panic, OCD, PTSD, adjustment |
| F50-F59 | Behavioral syndromes associated with physiological disturbances and physical factors | Eating disorders, sleep disorders not due to a substance |
| F60-F69 | Disorders of adult personality and behavior | Borderline personality disorder |
| F70-F79 | Intellectual disabilities | Mild to profound intellectual disability |
| F80-F89 | Pervasive and specific developmental disorders | Autism, learning disorders |
| F90-F98 | Behavioral and emotional disorders with onset usually occurring in childhood and adolescence | ADHD, conduct disorder |
| F99 | Unspecified mental disorder | Mental disorder, not otherwise specified |
What Changed in FY2027 (and Recent Years)
The FY2027 update added one Chapter 5 code, F64.A (Gender identity disorder, in remission), and did not delete or revise any existing F code. Claims for services on or after October 1, 2026 must use the FY2027 set; services before that date use the FY2026 set, even if the claim is filed later.
| Fiscal year | Mental health change | Why it matters |
|---|---|---|
| FY2027 | New F64.A, Gender identity disorder, in remission | Only new F code this year |
| FY2025 | Eating disorders expanded by severity and remission, such as F50.010 to F50.014 and F50.810 to F50.814 | Old 5-character codes like F50.01 and F50.81 are no longer billable |
| FY2023 | New F43.81, Prolonged grief disorder | Replaces nonspecific grief coding |
| FY2022 | New F32.A, Depression, unspecified | Distinct from F32.9, major depressive disorder |
Depression ICD-10 Codes
Depression coding turns on three facts the note must state: single or recurrent episode, severity, and remission status. Missing any one pushes the coder to an unspecified code.
| Code | ICD-10-CM title | Use when the note documents |
|---|---|---|
| F32.0 | Major depressive disorder, single episode, mild | First episode, mild severity |
| F32.1 | Major depressive disorder, single episode, moderate | First episode, moderate severity |
| F32.2 | Major depressive disorder, single episode, severe without psychotic features | First episode, severe, no psychosis |
| F32.3 | Major depressive disorder, single episode, severe with psychotic features | First episode, severe, with psychosis |
| F32.9 | Major depressive disorder, single episode, unspecified | MDD, single episode, severity not stated |
| F32.A | Depression, unspecified | Depression without MDD criteria documented |
| F33.0 / F33.1 / F33.2 | Major depressive disorder, recurrent, mild / moderate / severe without psychotic features | Recurrent episodes with stated severity |
| F33.41 / F33.42 | Major depressive disorder, recurrent, in partial / full remission | Recurrent MDD now in remission |
| F34.1 | Dysthymic disorder | Persistent depressive disorder |
Anxiety, OCD, Trauma and Adjustment Codes
| Code | ICD-10-CM title | Coding note |
|---|---|---|
| F41.1 | Generalized anxiety disorder | Most specific code for GAD |
| F41.0 | Panic disorder [episodic paroxysmal anxiety] | Panic without agoraphobia |
| F41.9 | Anxiety disorder, unspecified | Use only when type is not documented |
| F40.10 | Social phobia, unspecified | DSM-5-TR social anxiety disorder |
| F42.2 | Mixed obsessional thoughts and acts | DSM-5-TR obsessive-compulsive disorder |
| F43.0 | Acute stress reaction | Acute response to a traumatic event |
| F43.10 / F43.11 / F43.12 | Post-traumatic stress disorder, unspecified / acute / chronic | Document acute or chronic to avoid F43.10 |
| F43.21 / F43.22 / F43.23 | Adjustment disorder with depressed mood / with anxiety / with mixed anxiety and depressed mood | Very common in outpatient therapy |
| F43.81 | Prolonged grief disorder | Added in FY2023 |
For phobia subtypes and agoraphobia codes, see our dedicated anxiety ICD-10 codes guide. When a patient reports concentration or memory problems without a mental health diagnosis, our brain fog ICD-10 code guide covers R41.840 and related symptom codes.
Bipolar, Psychotic and Personality Disorder Codes
| Code | ICD-10-CM title | Coding note |
|---|---|---|
| F31.81 | Bipolar II disorder | Specific code; no episode subtype needed |
| F31.9 | Bipolar disorder, unspecified | Other F31 codes capture the current episode, severity and remission |
| F20.9 | Schizophrenia, unspecified | Type-specific codes exist, such as F20.1 Disorganized schizophrenia |
| F25.0 | Schizoaffective disorder, bipolar type | Separate code for depressive type |
| F60.3 | Borderline personality disorder | Often paired with a mood or trauma code |
ADHD, Autism and Eating Disorder Codes
| Code | ICD-10-CM title | Coding note |
|---|---|---|
| F90.0 | Attention-deficit hyperactivity disorder, predominantly inattentive type | Presentation documented as inattentive |
| F90.1 | Attention-deficit hyperactivity disorder, predominantly hyperactive type | Presentation documented as hyperactive-impulsive |
| F90.2 | Attention-deficit hyperactivity disorder, combined type | Both presentations documented |
| F90.9 | Attention-deficit hyperactivity disorder, unspecified type | Use only when presentation is not stated |
| F84.0 | Autistic disorder | DSM-5-TR autism spectrum disorder |
| F50.810 to F50.814 | Binge eating disorder, mild to in remission | Severity required since FY2025; F50.819 if unspecified |
Substance Use Disorder Codes
Codes F10 to F19 are organized by substance. The fourth character shows the pattern: .1 for abuse, .2 for dependence and .9 for use. Further characters capture remission and any substance-induced disorder.
| Code | ICD-10-CM title | Coding note |
|---|---|---|
| F10.20 | Alcohol dependence, uncomplicated | DSM-5-TR moderate or severe alcohol use disorder |
| F11.20 | Opioid dependence, uncomplicated | Common in medication for opioid use disorder programs |
| F12.20 | Cannabis dependence, uncomplicated | Code remission status when documented |
For H-codes, levels of care and authorization, see our guide to revenue cycle management for addiction treatment. Programs that bill substance use services under separate payer rules can see our addiction treatment billing services.
Z Codes and Social Determinants of Health
Z codes describe circumstances that affect health, such as housing, finances or family stress. CMS guidance says any member of the care team can collect SDOH information, and coders can assign Z55 to Z65 codes from self-reported data or care team notes, as long as it is in the official medical record.
| Code | ICD-10-CM title | Where it fits |
|---|---|---|
| Z59.00 | Homelessness unspecified | Housing instability |
| Z59.41 | Food insecurity | Economic circumstances |
| Z56.0 | Unemployment, unspecified | Employment problems |
| Z63.0 | Problems in relationship with spouse or partner | Primary support group |
| Z91.51 | Personal history of suicidal behavior | Risk factor, not an SDOH code |
| Z13.31 | Encounter for screening for depression | Screening visits, such as with CPT 96127 |
Do not list a Z code as the only diagnosis on a psychotherapy claim unless the payer’s policy allows it. Many plans treat relationship or life-stress Z codes as non-covered on their own. When the clinician documents a disorder, such as an adjustment disorder, code that first and add the Z code for context.
ICD-10-CM vs DSM-5-TR Naming
Clinicians diagnose with DSM-5-TR criteria, but the claim must carry the ICD-10-CM code, which is the HIPAA code set. DSM-5-TR lists the matching ICD-10-CM code for each diagnosis, yet the official ICD-10-CM title is often worded differently. That is normal and does not need correcting.
| DSM-5-TR diagnosis | ICD-10-CM title on the claim | Code |
|---|---|---|
| Persistent depressive disorder | Dysthymic disorder | F34.1 |
| Social anxiety disorder | Social phobia, unspecified | F40.10 |
| Obsessive-compulsive disorder | Mixed obsessional thoughts and acts | F42.2 |
| Autism spectrum disorder | Autistic disorder | F84.0 |
| Unspecified depressive disorder | Depression, unspecified | F32.A |
Specificity Rules That Prevent Denials
- Use the right year. Match the code set to the date of service, not the date the claim is sent.
- Code to the last character. A category like F43.1 or F33.4 is not billable; the claim needs the full code, such as F43.12 or F33.41.
- List the main reason first. The first-listed diagnosis should be the condition chiefly responsible for the visit, followed by other conditions that affect treatment.
- Skip uncertain diagnoses. In outpatient settings, do not code probable, suspected or rule-out diagnoses. Code the documented signs or symptoms instead.
- Match the diagnosis to the service. A diagnosis that does not support the CPT code can trigger a CO-11 denial for a diagnosis inconsistent with the procedure.
Worked Example
A therapist sees an adult client for a 50-minute session. The note describes a second major depressive episode, moderate severity, plus anxiety linked to a recent job loss. The client is not currently employed.
Correct coding. F33.1 (recurrent, moderate) first, then Z56.0 (unemployment, unspecified) for context, with CPT 90834 for the session.
Weaker coding. F32.9 alone ignores the recurrent episode and the severity in the note, and Z56.0 alone would leave the session without a covered diagnosis.
For the session code, time rules and claim steps, follow our guide on how to bill for mental health therapy.
Codes That Are Often Confused
| Pair | The difference | Tip |
|---|---|---|
| F32.9 vs F32.A | Major depressive disorder vs depression not meeting MDD | Pick the code that matches the clinician’s diagnosis |
| F32.x vs F33.x | Single episode vs recurrent | Check history for prior episodes |
| F41.9 vs F41.1 | Unspecified anxiety vs GAD | Ask for the specific disorder if criteria are met |
| F43.2x vs F32.x | Adjustment disorder vs major depression | Adjustment disorder ties symptoms to a stressor |
| Z63.0 vs F43.2x | Life problem vs diagnosable disorder | Z code supports context, not usually coverage |
Diagnosis errors show up as medical necessity and code-mismatch denials. Our guide to behavioral health billing denials explains how to work and prevent them.
Need diagnosis and procedure codes checked before every claim goes out? Steady Medical Billing’s certified coding team reviews behavioral health documentation and codes it to the highest supported specificity.
Frequently Asked Questions
What ICD-10 codes are used for mental health?
Mental health diagnoses use Chapter 5 of ICD-10-CM, codes F01 to F99. Common outpatient codes include F32 and F33 for depression, F41.1 for generalized anxiety disorder, F43 codes for PTSD and adjustment disorders, and F90 codes for ADHD.
Did FY2027 change any mental health ICD-10 codes?
Only one. FY2027, effective October 1, 2026, added F64.A, Gender identity disorder, in remission. No other F codes were added, deleted or revised.
What is the difference between F32.9 and F32.A?
F32.9 is major depressive disorder, single episode, unspecified. F32.A is depression, unspecified, for depression that is not documented as major depressive disorder. Choose the one that matches the clinician’s diagnosis.
Can a Z code be the primary diagnosis for therapy?
Some payers allow it, but many do not cover psychotherapy when a Z code such as Z63.0 is the only diagnosis. If the clinician documents a disorder, list that first and add the Z code for context.
Should I use the DSM-5-TR name or the ICD-10-CM title?
The claim carries the ICD-10-CM code. DSM-5-TR names can differ from the ICD-10-CM titles, for example persistent depressive disorder maps to F34.1 Dysthymic disorder, and that difference is expected.
