What is ICD-10 code F43.10?

F43.10 is the ICD-10-CM diagnosis code for Post-traumatic stress disorder, unspecified. A mental health condition that develops after exposure to a traumatic event, characterized by intrusive memories, avoidance behaviors, and hyperarousal, without specification of whether it is acute or chronic. F43.10 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. F43.10 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. F43.10 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. F43.10 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.

What is the V28 vs V24 difference for F43.10?

F43.10 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards F43.10 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting F43.10?

Use this code only when the duration or onset pattern is not documented; specify acute (F43.11) or chronic (F43.12) when information is available Document the traumatic event and symptoms present to support the diagnosis

F43.10 ICD-10 Code: Post-traumatic stress

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 lookupF43.10Effective 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)

F43.10

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

Post-traumatic stress disorder, unspecified

A mental health condition that develops after exposure to a traumatic event, characterized by intrusive memories, avoidance behaviors, and hyperarousal, without specification of whether it is acute or chronic.

Buddy Insight

Post-traumatic stress disorder, unspecified, is used when PTSD is documented without specification as acute or chronic.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 133

Personality Disorders, Anxiet...

RAF 0.0

Code Trumping

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Code Book Path

Official

F43Reaction to severe stress, and adjustment disorders

F43.1Post-traumatic stress disorder (PTSD)

F43.10Post-traumatic stress disorder, unspecified

Inclusion Terms

Official

Traumatic neurosis

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for F43.10 in this effective period.

Related Child Codes

Official

F43.11Post-traumatic stress disorder, acute

F43.12Post-traumatic stress disorder, chronic

Includes

Official

ICD-10-CM does not list Includes notes for F43.10 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for F43.10 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for F43.10 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for F43.10 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for F43.10 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Exposure to a traumatic event (actual or threatened death, serious injury, sexual violence)

Re-experiencing symptoms (intrusive memories, nightmares, flashbacks, distress at reminders)

Avoidance of trauma-related stimuli (thoughts, feelings, external reminders)

Negative alterations in cognitions and mood (amnesia, negative beliefs, detachment, diminished interest)

MEAT Support

HCC Buddy guidance

Exposure to a traumatic event (actual or threatened death, serious injury, sexual violence)

Re-experiencing symptoms (intrusive memories, nightmares, flashbacks, distress at reminders)

Avoidance of trauma-related stimuli (thoughts, feelings, external reminders)

Negative alterations in cognitions and mood (amnesia, negative beliefs, detachment, diminished interest)

Audit Caution

HCC Buddy guidance

Using F43.10 when documentation specifies acute or chronic duration — query for specificity

Confusing acute stress disorder (F43.0) with acute PTSD (F43.11) — they have different timeframes and diagnostic criteria

Coding PTSD without documented exposure to a qualifying traumatic event

Not distinguishing PTSD from adjustment disorder when the stressor does not meet criterion A for trauma

Common Mistakes

HCC Buddy guidance

F43.11 (Post-traumatic stress disorder, acute) — Use when symptoms have been present for less than 3 months following the traumatic event

F43.12 (Post-traumatic stress disorder, chronic) — Use when symptoms have persisted for 3 months or longer

F43.0 (Acute stress disorder) — Acute stress disorder occurs within 3 days to 1 month after trauma; PTSD requires symptoms beyond 1 month

F43.20 (Adjustment disorder, unspecified) — Adjustment disorder involves less severe reactions to stressors that may not meet PTSD diagnostic criteria

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is F43.10 an HCC code?

No. F43.10 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

RxHCCHCC 133, Personality Disorders, Anxiety, and Other Specified Mental Disorders

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

MEAT Criteria for F43.10

For F43.10to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

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

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed F43.10 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

F43.10 is the ICD-10-CM diagnosis code for post-traumatic stress disorder, unspecified. A mental health condition that develops after exposure to a traumatic event, characterized by intrusive memories, avoidance behaviors, and hyperarousal, without specification of whether it is acute or chronic. F43.10 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).

F43.10 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

F43.10 does not map to any HCC under V24 or V28 and has no RAF weight. No ESRD mapping. RxHCC maps to RxHCC 133 at 0.0 weight. Despite being a significant psychiatric condition with high resource utilization, PTSD is not a risk-adjusting diagnosis under current CMS-HCC models.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for F43.10 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 duration or onset pattern is not documented; specify acute (F43.11) or chronic (F43.12) when information is available
•Document the traumatic event and symptoms present to support the diagnosis

Clinical Significance

Post-traumatic stress disorder, unspecified, is used when PTSD is documented without specification as acute or chronic. PTSD is a significant psychiatric condition that develops after exposure to traumatic events and involves re-experiencing, avoidance, negative cognitions/mood changes, and hyperarousal. It does not map to any HCC under V24 or V28 despite being a high-resource-utilization condition.

Documentation Requirements

✓Exposure to a traumatic event (actual or threatened death, serious injury, sexual violence)
✓Re-experiencing symptoms (intrusive memories, nightmares, flashbacks, distress at reminders)
✓Avoidance of trauma-related stimuli (thoughts, feelings, external reminders)
✓Negative alterations in cognitions and mood (amnesia, negative beliefs, detachment, diminished interest)
✓Alterations in arousal and reactivity (hypervigilance, exaggerated startle, irritability, sleep disturbance)
✓Duration of symptoms exceeding 1 month
✓Current treatment plan (trauma-focused CBT, EMDR, pharmacotherapy)

Commonly Confused Codes

•F43.11 (Post-traumatic stress disorder, acute) — Use when symptoms have been present for less than 3 months following the traumatic event
•F43.12 (Post-traumatic stress disorder, chronic) — Use when symptoms have persisted for 3 months or longer
•F43.0 (Acute stress disorder) — Acute stress disorder occurs within 3 days to 1 month after trauma; PTSD requires symptoms beyond 1 month
•F43.20 (Adjustment disorder, unspecified) — Adjustment disorder involves less severe reactions to stressors that may not meet PTSD diagnostic criteria