F41.9
F41 — Other anxiety disorders
Chapter 5: Mental, Behavioral and Neurodevelopmental Disorders (F01-F99)
F40-F48 — Anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders
Clinical Definition
Anxiety disorder, unspecified (F41.9) refers to a clinically significant anxiety condition that does not meet the full diagnostic criteria for a more specific anxiety disorder or for which the clinician has not yet determined the precise subtype. The patient presents with persistent, excessive worry, apprehension, or fear that causes functional impairment or marked distress, but the clinical picture either lacks sufficient detail for a more granular classification or the evaluation is still in progress. Common presenting symptoms include restlessness, muscle tension, irritability, difficulty concentrating, sleep disturbance, and autonomic hyperarousal such as palpitations, sweating, and gastrointestinal distress.
F41.9 is appropriate when the provider documents "anxiety disorder" or "anxiety" as a diagnosis without specifying whether it is generalized anxiety disorder, panic disorder, mixed anxiety and depressive disorder, or another defined subtype. This code functions as the default for anxiety disorder NOS (not otherwise specified) and anxiety state NOS. It should not be used when the clinical documentation supports a more specific code such as F41.0 (panic disorder without agoraphobia), F41.1 (generalized anxiety disorder), or F40.10 (social anxiety disorder). Coders should query the provider when documentation suggests features of a specific anxiety subtype but the diagnosis is documented in general terms.
In terms of DSM-5-TR alignment, F41.9 most closely maps to the DSM-5-TR category of "Unspecified Anxiety Disorder" (300.00), which is used when anxiety symptoms cause clinically significant distress or impairment but do not meet the full criteria for any specific anxiety disorder, or when there is insufficient information to make a more specific diagnosis. This code is frequently used during initial psychiatric evaluations, emergency department encounters, and primary care visits where a comprehensive anxiety assessment has not yet been completed.
When to Use F41.9
- ✓The provider documents 'anxiety disorder' or 'anxiety' without specifying a subtype such as generalized anxiety disorder, panic disorder, social anxiety disorder, or another specific diagnosis.
- ✓The patient presents with clinically significant anxiety symptoms during an initial evaluation or emergency department visit where a full diagnostic workup has not yet been completed.
- ✓The clinical presentation includes mixed anxiety features that do not clearly meet the criteria for any single specific anxiety disorder under F40 or F41.
- ✓The patient has a known anxiety condition being managed with anxiolytic medication or psychotherapy, but the medical record does not specify the exact type of anxiety disorder.
- ✓A primary care provider documents 'anxiety state' or 'anxiety NOS' as a working diagnosis while awaiting psychiatric consultation or further evaluation.
- ✓The patient's anxiety symptoms are being treated symptomatically but the underlying anxiety disorder subtype has not been formally established through structured diagnostic assessment.
Common Coding Mistakes
- ⚠Using F41.9 when the documentation clearly describes recurrent, unexpected panic attacks with anticipatory anxiety. If panic attacks are the predominant feature, F41.0 (panic disorder without agoraphobia) is the correct code.
- ⚠Assigning F41.9 when the provider documents chronic, excessive worry about multiple life domains lasting six months or more with associated physical symptoms. This clinical picture supports F41.1 (generalized anxiety disorder), which should be used instead.
- ⚠Confusing F41.9 with F43.22 (adjustment disorder with anxiety). If the anxiety is clearly linked to an identifiable psychosocial stressor with onset within three months of the stressor, F43.22 is more appropriate.
- ⚠Using F41.9 for normal or situational anxiety that does not constitute a clinical disorder. Everyday stress responses and normal worry do not warrant an anxiety disorder diagnosis code.
- ⚠Assigning F41.9 when the anxiety is a direct physiological consequence of a medical condition (e.g., hyperthyroidism, pheochromocytoma). In such cases, F06.4 (anxiety disorder due to known physiological condition) should be used, sequenced after the underlying medical condition.
- ⚠Failing to query the provider when the clinical documentation contains enough detail to support a more specific anxiety diagnosis. Coders should always attempt to capture the highest level of specificity supported by the record.
Related & Differential Codes
| Code | Description | Relationship |
|---|---|---|
| F41.0 | Panic disorder [episodic paroxysmal anxiety] | Sibling |
| F41.1 | Generalized anxiety disorder | Sibling |
| F41.3 | Other mixed anxiety disorders | Sibling |
| F41.8 | Other specified anxiety disorders | Sibling |
| F41 | Other anxiety disorders (category) | Parent |
| F40.10 | Social phobia, unspecified | Related |
| F40.00 | Agoraphobia, unspecified | Related |
| F32.9 | Major depressive disorder, single episode, unspecified | Related |
| F43.22 | Adjustment disorder with anxiety | Related |
| F43.23 | Adjustment disorder with mixed anxiety and depressed mood | Related |
| F06.4 | Anxiety disorder due to known physiological condition | Excludes |
| F42.9 | Obsessive-compulsive disorder, unspecified | Related |
| F43.10 | Post-traumatic stress disorder, unspecified | Related |
Documentation Requirements
- 1Document the specific anxiety symptoms present, including psychological symptoms (excessive worry, apprehension, fear, difficulty concentrating, irritability) and physical symptoms (muscle tension, restlessness, sleep disturbance, palpitations, sweating, gastrointestinal complaints).
- 2Record the duration, frequency, and severity of anxiety symptoms, including their impact on occupational, social, and daily functioning.
- 3Specify whether the anxiety meets criteria for a particular anxiety disorder subtype (generalized anxiety disorder, panic disorder, social anxiety disorder, specific phobia) or document why a more specific diagnosis cannot be established at this time.
- 4Note any identifiable precipitating factors, psychosocial stressors, or triggering situations associated with the anxiety symptoms.
- 5Document any comorbid psychiatric conditions, particularly depression, substance use disorders, or other anxiety spectrum disorders, and whether the anxiety is a primary or secondary diagnosis.
- 6Record current and prior treatments for anxiety, including medications (SSRIs, SNRIs, benzodiazepines, buspirone), psychotherapy modalities (CBT, exposure therapy), and patient response to treatment.
- 7Include relevant screening tool scores (GAD-7, PHQ-4, Hamilton Anxiety Rating Scale, Beck Anxiety Inventory) to quantify symptom severity and track treatment response.
- 8Document any medical conditions that could be contributing to or mimicking anxiety symptoms (thyroid disorders, cardiac arrhythmias, substance withdrawal, medication side effects) and whether these have been evaluated or ruled out.
Reimbursement & Billing Notes
F41.9 is a valid, billable ICD-10-CM code accepted by Medicare, Medicaid, and all major commercial payers. It supports reimbursement for evaluation and management visits, psychiatric diagnostic evaluations (CPT 90791, 90792), psychotherapy services (CPT 90832, 90834, 90837), pharmacologic management, and screening assessments. The code is commonly used in primary care, psychiatry, and emergency medicine settings. When billing for psychotherapy, ensure the documentation supports the time-based CPT code selected and includes a treatment plan addressing the anxiety diagnosis.
Payers generally do not require prior authorization for initial psychiatric evaluation or outpatient psychotherapy for anxiety disorders, though some plans may impose session limits or require treatment plans for continued coverage. For pharmacologic management, most first-line anxiolytic medications (SSRIs, SNRIs, buspirone) are covered under standard formularies, while benzodiazepines may require step therapy documentation or prior authorization. If the patient requires intensive outpatient programs or partial hospitalization for severe anxiety, additional clinical justification documenting functional impairment and failure of outpatient treatment will typically be required. Note that some payers may flag frequent use of F41.9 and request clarification for why a more specific anxiety diagnosis has not been established, particularly for ongoing treatment beyond the initial evaluation period.
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Try Free — No Credit Card RequiredFrequently Asked Questions
What is the ICD-10 code for anxiety?
The most commonly used ICD-10 code for anxiety is F41.9 (Anxiety disorder, unspecified). This code is appropriate when a provider documents 'anxiety' or 'anxiety disorder' without specifying a particular subtype. If the anxiety has been further characterized, more specific codes are available: F41.1 for generalized anxiety disorder (GAD), F41.0 for panic disorder, F40.10 for social anxiety disorder, and F40.00 for agoraphobia. F41.9 is the default code used when the type of anxiety disorder has not been determined or specified in the clinical documentation.
What is the difference between F41.1 and F41.9?
F41.1 is the ICD-10 code for generalized anxiety disorder (GAD), a specific anxiety diagnosis characterized by persistent, excessive worry about multiple life domains (work, health, finances, daily matters) lasting at least six months, accompanied by at least three physical or cognitive symptoms such as restlessness, fatigue, difficulty concentrating, irritability, muscle tension, or sleep disturbance. F41.9 is the code for anxiety disorder, unspecified, used when the provider documents anxiety but does not specify GAD or another particular subtype. If the clinical documentation supports a GAD diagnosis, F41.1 should be used as it provides greater specificity. F41.9 should only be used when the documentation does not support a specific subtype.
Can F41.9 be used with depression codes?
Yes, F41.9 can be coded alongside depression codes such as F32.9 (major depressive disorder, single episode, unspecified) or F33.0-F33.9 (major depressive disorder, recurrent) when both conditions are documented and treated as separate diagnoses. Anxiety and depression frequently co-occur, and both should be reported when clinically present and addressed by the provider. However, if the clinical picture is best characterized as a mixed state, consider F41.8 (other specified anxiety disorders), which includes mixed anxiety and depressive disorder when neither condition predominates. The sequencing of anxiety and depression codes depends on the primary reason for the encounter.
What is the difference between F41.9 and F43.22?
F41.9 (anxiety disorder, unspecified) is used for anxiety that is not tied to a specific identifiable stressor and represents a primary anxiety disorder. F43.22 (adjustment disorder with anxiety) is used when anxiety symptoms develop in response to an identifiable psychosocial stressor (such as job loss, divorce, medical diagnosis, or relocation) within three months of the stressor's onset and are expected to resolve within six months after the stressor or its consequences have ended. The key distinction is whether the anxiety is stressor-related (F43.22) or represents a primary, independent anxiety condition (F41.9). If the documentation links the anxiety directly to a specific stressor, F43.22 is typically more appropriate.
Is F41.9 a billable code accepted by Medicare?
Yes, F41.9 is a fully billable and valid ICD-10-CM code that is accepted by Medicare, Medicaid, and all major commercial insurance payers. It does not require additional digits or characters and can be used as either a primary or secondary diagnosis code. F41.9 supports reimbursement for evaluation and management services, psychiatric evaluations, psychotherapy, medication management, and anxiety screening. It is one of the most frequently reported mental health diagnosis codes across all clinical settings.
When should I use F41.9 vs F06.4 for anxiety?
F41.9 (anxiety disorder, unspecified) is used for primary anxiety disorders where the anxiety is not attributable to a known medical condition. F06.4 (anxiety disorder due to known physiological condition) is used when the anxiety is a direct physiological consequence of a medical condition such as hyperthyroidism, pheochromocytoma, cardiac arrhythmia, chronic obstructive pulmonary disease, or vestibular dysfunction. When using F06.4, the underlying medical condition must be coded first, followed by F06.4. The distinction requires clinical judgment: if the anxiety is caused by the medical condition's pathophysiology (not simply a psychological reaction to being ill), F06.4 is appropriate. If the anxiety is a primary psychiatric condition that coexists with a medical condition but is not caused by it, F41.9 is correct.