What is ICD-10 code F43.20?

F43.20 is the ICD-10-CM diagnosis code for Adjustment disorder, unspecified. A temporary emotional or behavioral problem that develops in response to a specific identifiable stressor, without specification of the predominant symptoms. It belongs to the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99). F43.20 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. F43.20 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. F43.20 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. F43.20 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does F43.20 map to under V28?

F43.20 has no payable CMS-HCC V28 mapping in the final FY2026 CMS file.

What RAF reference is published for F43.20?

F43.20 has no V28 reference coefficient because the final FY2026 source verifies no payable V28 mapping.

What is the V28 vs V24 difference for F43.20?

F43.20 has verified no payable V28 mapping in the final FY2026 source. Select a historical effective period before making any V24 comparison.

What documentation supports F43.20?

Use this code only when the specific type of adjustment disorder is not documented; specify the predominant feature when known (F43.21, F43.23, F43.25) Document the identifiable stressor and the timing of symptom onset relative to the stressor F43.20 is not a CMS-HCC V28 payment code in the verified current source, so MEAT is not the payment hook. Documentation still has to support the diagnosis if you report it.

2026 ICD-10-CM F43.20: Adjustment disorder, unspecified

F43.20 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · free HCC coding tools

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupF43.20

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders (F40-F48)

F43.20

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Adjustment disorder, unspecified

A temporary emotional or behavioral problem that develops in response to a specific identifiable stressor, without specification of the predominant symptoms.

Buddy Insight

Adjustment disorder, unspecified, is used when a patient develops emotional or behavioral symptoms in response to an identifiable stressor but the specific subtype (depressed mood, anxiety, mixed, conduct disturbance) is not documented.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

Mapped

HCC 133

Anxiety and Other Psychiatric...

Code-level coefficient reference

Code Book Path

Official

F43Reaction to severe stress, and adjustment disorders F43.2Adjustment disorders F43.20Adjustment disorder, unspecified

Inclusion Terms

Official

Culture shockInherited from F43.2
Grief reactionInherited from F43.2
Hospitalism in childrenInherited from F43.2

Excludes 2

Official

symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)Inherited from F01-F99, F43.2
separation anxiety disorder of childhood (F93.0)Inherited from F01-F99, F43.2

Related Codes

Official

F43.21Adjustment disorder with depressed mood F43.22Adjustment disorder with anxiety F43.23Adjustment disorder with mixed anxiety and depressed mood F43.24Adjustment disorder with disturbance of conduct F43.25Adjustment disorder with mixed disturbance of emotions and conduct

Includes

Official

disorders of psychological developmentInherited from F01-F99

Excludes 1

Official

No Excludes 1 notes are included in this display for F43.20. Check the code and parent instructions in the Code Book.

Code First

Official

No Code First sequencing instructions are included in this display for F43.20. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for F43.20. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for F43.20. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Identifiable stressor documented with temporal relationship to symptom onset

Emotional or behavioral symptoms developing within 3 months of the stressor

Symptoms are clinically significant (marked distress beyond expected or functional impairment)

Symptoms do not meet criteria for another specific mental disorder

MEAT Support

HCC Buddy guidance

Identifiable stressor documented with temporal relationship to symptom onset

Emotional or behavioral symptoms developing within 3 months of the stressor

Symptoms are clinically significant (marked distress beyond expected or functional impairment)

Symptoms do not meet criteria for another specific mental disorder

Audit Caution

HCC Buddy guidance

Using the unspecified code when documentation contains enough detail to assign a specific subtype

Coding adjustment disorder when symptoms actually meet criteria for MDD, GAD, or another specific disorder

Not documenting the specific stressor that precipitated the adjustment disorder

Continuing to code adjustment disorder beyond 6 months after the stressor has resolved — consider reclassification

Common Mistakes

HCC Buddy guidance

F43.21 (Adjustment disorder with depressed mood) — Use when depressed mood predominates

F43.22 (Adjustment disorder with anxiety) — Use when anxiety predominates

F43.23 (Adjustment disorder with mixed anxiety and depressed mood) — Use when both are present

F32.9 (Major depressive disorder, single episode, unspecified) — MDD is more severe and may persist without a stressor; adjustment disorder is reactive

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is F43.20 an HCC code?

F43.20 is not in the CMS-HCC V28 or V24 community payment model. F43.20 has a separate mapping under the Part D RxHCC model (HCC 133 (Anxiety and Other Psychiatric Disorders)); the applicable result needs member context.

Code: F43.20
Description: Adjustment disorder, unspecified
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

RxHCCHCC 133, Anxiety and Other Psychiatric Disorders

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work F43.20 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for F43.20

For F43.20, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Coder workflow notes

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What This Code Means

F43.20 is the ICD-10-CM diagnosis code for adjustment disorder, unspecified. A temporary emotional or behavioral problem that develops in response to a specific identifiable stressor, without specification of the predominant symptoms. F43.20 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering anxiety, dissociative, stress-related, somatoform and other nonpsychotic mental disorders (f40-f48).

F43.20 has no mapping under the CMS-HCC V28 or V24 community payment models. F43.20 has a separate mapping under the Part D RxHCC model (HCC 133 (Anxiety and Other Psychiatric Disorders)); the applicable result needs member context. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.

Use this code only when the specific type of adjustment disorder is not documented; specify the predominant feature when known (F43.21, F43.23, F43.25).

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for F43.20 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code only when the specific type of adjustment disorder is not documented; specify the predominant feature when known (F43.21, F43.23, F43.25)
•Document the identifiable stressor and the timing of symptom onset relative to the stressor

Clinical Significance

Documentation Requirements

✓Identifiable stressor documented with temporal relationship to symptom onset
✓Emotional or behavioral symptoms developing within 3 months of the stressor
✓Symptoms are clinically significant (marked distress beyond expected or functional impairment)
✓Symptoms do not meet criteria for another specific mental disorder
✓Symptoms do not represent normal bereavement
✓Expected to resolve within 6 months after the stressor or its consequences end

Commonly Confused Codes

•F43.21 (Adjustment disorder with depressed mood): Use when depressed mood predominates
•F43.22 (Adjustment disorder with anxiety): Use when anxiety predominates
•F43.23 (Adjustment disorder with mixed anxiety and depressed mood): Use when both are present
•F32.9 (Major depressive disorder, single episode, unspecified): MDD is more severe and may persist without a stressor; adjustment disorder is reactive
•F43.10 (PTSD, unspecified): PTSD requires a criterion A trauma; adjustment disorder can follow any stressor