ICD-10 Codes for Anxiety and Depression: Therapist Reference Guide

ICD-10 Codes for Anxiety and Depression: Therapist Reference Guide

Anxiety and depression are the two most common diagnoses in outpatient mental health — and they’re also among the most frequently miscoded. Using the wrong ICD-10 code can trigger claim denials, audits, or documentation mismatches that create headaches for you and your clients.

This guide covers the ICD-10 codes you’ll use most often for anxiety and depression, how to choose between them, and what your documentation needs to support each one.


ICD-10 Codes for Anxiety Disorders

Generalized Anxiety Disorder

F41.1 — Generalized Anxiety Disorder

The most common anxiety code in outpatient therapy. GAD requires excessive worry occurring more days than not for at least six months, about multiple domains, that the client finds difficult to control. Associated symptoms include fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbance — at least three for adults.

Document to support F41.1:

  • Duration of worry (6+ months)
  • Multiple worry domains (work, health, family, finances)
  • Difficulty controlling the worry
  • At least 3 associated somatic/cognitive symptoms
  • Functional impairment (sleep, relationships, work performance)
  • Panic Disorder

    F41.0 — Panic Disorder

    Recurrent unexpected panic attacks followed by at least one month of anticipatory anxiety or significant behavioral change (avoidance). The “unexpected” qualifier matters — if panic attacks are consistently triggered by a specific stimulus, look at specific phobia or social anxiety instead.

    Social Anxiety Disorder (Social Phobia)

    F40.10 — Social Phobia, Unspecified

    F40.11 — Social Phobia, Generalized

    Use F40.11 when anxiety spans most social situations. Use F40.10 for more limited social fear (e.g., primarily performance situations). Both require marked fear of scrutiny and significant impairment or distress.

    Specific Phobia

    F40.218 — Other Specified Phobia (use when no more specific code applies)

    F40.241 — Fear of heights

    F40.242 — Claustrophobia

    F40.240 — Fear of flying

    F40.230 — Fear of blood

    When a more specific code exists, use it. When it doesn’t, F40.218 covers most presentations.

    Agoraphobia

    F40.00 — Agoraphobia Without Panic Disorder

    F40.01 — Agoraphobia With Panic Disorder

    Always specify the presence or absence of panic disorder — they’re distinct clinical presentations with different treatment implications.

    Anxiety Disorder, Unspecified

    F41.9 — Anxiety Disorder, Unspecified

    Appropriate when anxiety clearly causes distress and impairment but doesn’t meet full criteria for a more specific diagnosis — or early in treatment while assessment is still in progress. Revisit and update once your clinical picture is clearer.


    ICD-10 Codes for Depressive Disorders

    Major Depressive Disorder

    MDD coding in ICD-10 uses episode specifiers. You’ll see both single-episode and recurrent-episode codes.

    Single Episode:

  • F32.0 — Major Depressive Disorder, Single Episode, Mild
  • F32.1 — Major Depressive Disorder, Single Episode, Moderate
  • F32.2 — Major Depressive Disorder, Single Episode, Severe Without Psychotic Features
  • F32.3 — Major Depressive Disorder, Single Episode, Severe With Psychotic Features
  • F32.4 — Major Depressive Disorder, Single Episode, In Partial Remission
  • F32.5 — Major Depressive Disorder, Single Episode, In Full Remission
  • F32.9 — Major Depressive Disorder, Single Episode, Unspecified
  • Recurrent Episodes:

  • F33.0 — Major Depressive Disorder, Recurrent, Mild
  • F33.1 — Major Depressive Disorder, Recurrent, Moderate
  • F33.2 — Major Depressive Disorder, Recurrent, Severe Without Psychotic Features
  • F33.3 — Major Depressive Disorder, Recurrent, Severe With Psychotic Features
  • F33.40 — Major Depressive Disorder, Recurrent, In Remission, Unspecified
  • F33.9 — Major Depressive Disorder, Recurrent, Unspecified
  • How to choose severity:

  • Mild: Minimum symptoms (5), mild functional impairment
  • Moderate: More than minimum symptoms, moderate impairment
  • Severe: Nearly all criteria met, severe and observable impairment
  • Document to support an MDD code:

  • 5 or more depressive symptoms present for 2+ weeks
  • Depressed mood or loss of interest must be one of the 5
  • Significant functional impairment across domains
  • Rule-out of substance/medical etiology
  • Episode history (first or recurrent)
  • Persistent Depressive Disorder (Dysthymia)

    F34.1 — Persistent Depressive Disorder (Dysthymia)

    Depressed mood for most of the day, more days than not, for at least two years (one year for children/adolescents), plus at least two associated symptoms (appetite changes, sleep disturbance, low energy, poor concentration, low self-esteem, hopelessness). The key differentiator from MDD: chronic, lower-level persistence rather than episodic severity.

    Clients with dysthymia often don’t identify as “depressed” — they describe it as “just how they are.” Ask about chronicity and baseline mood, not just episodic lows.

    Depressive Episode, Unspecified

    F32.9 — Major Depressive Disorder, Single Episode, Unspecified

    F32.A — Depression, Unspecified (note: code availability varies by system)

    Use unspecified codes when a depressive episode is clearly present but you haven’t yet confirmed severity or episode history. These are appropriate for early sessions — update once your assessment is complete.

    Adjustment Disorder with Depressed Mood

    F43.21 — Adjustment Disorder with Depressed Mood

    When depressive symptoms develop in response to an identifiable stressor within three months of its onset, and the reaction is disproportionate or causes significant impairment — but full MDD criteria are not met.

    Don’t overuse this code. Adjustment disorder is time-limited by definition and should not persist beyond six months after the stressor resolves. If symptoms persist, reassess for MDD.


    Coding Mixed Anxiety and Depression

    Many clients present with clinically significant anxiety and depression simultaneously. ICD-10 handles this in a few ways.

    Code Both Separately

    The most defensible approach for most presentations: use both the relevant anxiety code and the relevant depressive disorder code on the claim. List the primary diagnosis first — the condition most related to your current treatment focus.

    Example: Client presents with GAD and moderate MDD. Primary focus is depressive symptoms.

  • Primary: F33.1 (MDD, Recurrent, Moderate)
  • Secondary: F41.1 (GAD)
  • Mixed Anxiety and Depressive Disorder

    F41.8 — Other Specified Anxiety Disorder

    ICD-10-CM doesn’t have a direct equivalent to ICD-10’s “mixed anxiety and depressive disorder” (F41.2) in the US clinical version. When symptoms of both are present but neither meets full criteria individually, F41.8 with documentation specifying the mixed presentation is the most appropriate option.


    ICD-10 Codes Quick Reference: Anxiety & Depression

    Code Diagnosis
    F41.1 Generalized Anxiety Disorder
    F41.0 Panic Disorder
    F40.10 Social Phobia, Unspecified
    F40.11 Social Phobia, Generalized
    F40.218 Specific Phobia, Other
    F40.00 Agoraphobia Without Panic
    F40.01 Agoraphobia With Panic Disorder
    F41.9 Anxiety Disorder, Unspecified
    F32.0 MDD, Single Episode, Mild
    F32.1 MDD, Single Episode, Moderate
    F32.2 MDD, Single Episode, Severe
    F32.9 MDD, Single Episode, Unspecified
    F33.0 MDD, Recurrent, Mild
    F33.1 MDD, Recurrent, Moderate
    F33.2 MDD, Recurrent, Severe
    F33.9 MDD, Recurrent, Unspecified
    F34.1 Persistent Depressive Disorder
    F43.21 Adjustment Disorder with Depressed Mood
    F43.23 Adjustment Disorder with Anxiety


    Documentation Tips for Anxiety and Depression Codes

    Be specific about symptoms. “Client reports feeling anxious” doesn’t support F41.1. Document the specific symptoms, their frequency, duration, and functional impact.

    Note episode history. For MDD, the single vs. recurrent distinction matters. Ask about prior episodes — including ones the client may not have recognized as depression at the time.

    Update codes as your assessment clarifies. It’s appropriate to start with an unspecified code and refine it once you have enough clinical data. Document your reasoning when you update.

    Verify current code lists. ICD-10-CM codes update annually. Always confirm codes against your current-year ICD-10-CM manual or a verified billing resource before submitting claims.


    For more clinical documentation resources — including progress note templates, CPT code guides, and private practice billing tools — visit the TherapistDesk resource library.

    Note: ICD-10-CM codes are updated annually. Always verify against the current code set before use in billing.

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