ICD-10 Codes for PTSD and Adjustment Disorders (F43)
PTSD and adjustment disorder ICD-10 codes for FY2027: F43.10, F43.11, F43.12, F43.0 and F43.20 to F43.29, plus F43.81 prolonged grief. Specificity tips.
PTSD is coded F43.10 unspecified, F43.11 acute or F43.12 chronic. Adjustment disorders run from F43.20 unspecified to F43.29, with the subtype in the last character, and acute stress reaction is F43.0. All sit in ICD-10-CM category F43 and none changed for FY2027 per CMS. In Ona, the chosen code feeds the visit's draft claim.
Quick answer:
- PTSD needs five characters: F43.10, F43.11 or F43.12. F43.1 on its own is a heading, not a billable code.
- Adjustment disorders carry the subtype in the fifth character: depressed mood, anxiety, mixed anxiety and depressed mood, conduct, mixed emotions and conduct, or other symptoms.
- Prolonged grief disorder has its own code, F43.81, and F43.9 covers trauma and stressor-related disorder that is unspecified.
The F43 Codes at a Glance
Every code and descriptor below comes from the FY2027 ICD-10-CM code descriptions, tabular list and index published by CMS, cross-checked on icd10data.com in October 2026. FY2027 codes apply to dates of service from October 1, 2026 to September 30, 2027.
| Code | Official FY2027 descriptor | Inclusion terms and notes |
|---|---|---|
| F43.0 | Acute stress reaction | Inclusion terms include acute reaction to stress and combat and operational stress reaction |
| F43.10 | Post-traumatic stress disorder, unspecified | F43.1 lists traumatic neurosis as an inclusion term |
| F43.11 | Post-traumatic stress disorder, acute | |
| F43.12 | Post-traumatic stress disorder, chronic | |
| F43.20 | Adjustment disorder, unspecified | F43.2 lists culture shock, grief reaction and hospitalism in children as inclusion terms |
| F43.21 | Adjustment disorder with depressed mood | |
| F43.22 | Adjustment disorder with anxiety | |
| F43.23 | Adjustment disorder with mixed anxiety and depressed mood | |
| F43.24 | Adjustment disorder with disturbance of conduct | |
| F43.25 | Adjustment disorder with mixed disturbance of emotions and conduct | |
| F43.29 | Adjustment disorder with other symptoms | |
| F43.81 | Prolonged grief disorder | Inclusion terms: complicated grief, complicated grief disorder, persistent complex bereavement disorder |
| F43.89 | Other reactions to severe stress | F43.8 lists other specified trauma and stressor-related disorder as an inclusion term |
| F43.9 | Reaction to severe stress, unspecified | Inclusion terms: trauma and stressor-related disorder NOS, unspecified trauma and stressor-related disorder |
The category title is "Reaction to severe stress, and adjustment disorders". F43, F43.1, F43.2 and F43.8 are all headings rather than billable codes, which is the single most common source of trouble in this family. The FY2027 guidelines put it plainly: a code is invalid if it has not been coded to the full number of characters required for that code. A superbill line reading "F43.1" or "F43.2" will reject.
PTSD: F43.10, F43.11, F43.12 and Chronicity
The fifth character of a PTSD code records chronicity: 0 unspecified, 1 acute, 2 chronic. The FY2027 index lists the same three paths under "Disorder, post-traumatic stress": no qualifier to F43.10, acute to F43.11, chronic to F43.12.
The ICD-10-CM tabular list does not define what makes PTSD acute or chronic. That is a clinical determination, and it belongs in the clinician's note. The coding job is narrower: if the note says chronic, the claim says F43.12; if the note says nothing about chronicity, the claim says F43.10.
Section I.B.18 of the FY2027 guidelines accepts unspecified codes when they "most accurately reflect what is known about the patient's condition at the time of that particular encounter". Section IV, which covers outpatient services, adds the other side: code to the highest level of specificity supported by the medical record. A long course of treatment billed every week as F43.10, with notes that describe the condition in more specific terms, is exactly the gap between documentation and claim that a records request finds. Some payer policies list the diagnoses they accept for particular services, and practices differ in how much attention unspecified codes draw; the details belong to each payer.
One related entry is easy to miss. The index sends "Reaction, post-traumatic stress, uncomplicated" to Z73.3, stress, not elsewhere classified. That is a Z code describing a factor influencing health status, not a PTSD diagnosis, and it should not stand in for one.
Acute Stress Reaction, F43.0
F43.0 is a single four-character billable code. Its inclusion terms in the FY2027 tabular list are acute crisis reaction, acute reaction to stress, combat and operational stress reaction, combat fatigue, crisis state and psychic shock.
Two cross-references matter. The anxiety category F41 lists acute stress reaction (F43.0) as an Excludes2, which under the guidelines means it is not part of the anxiety code and both may be reported when both are documented. And when a clinician's diagnosis moves from an acute stress reaction to PTSD, the chart should move with it, so the next claim does not carry a code the note no longer supports.
Adjustment Disorders: Six Subtypes and an Unspecified
The F43.2 codes are structured around the predominant presentation the clinician documents:
- F43.21 with depressed mood
- F43.22 with anxiety
- F43.23 with mixed anxiety and depressed mood
- F43.24 with disturbance of conduct
- F43.25 with mixed disturbance of emotions and conduct
- F43.29 with other symptoms
- F43.20 unspecified, when the subtype is not documented
The F43.2 subcategory carries three inclusion terms worth knowing: culture shock, grief reaction and hospitalism in children. It also carries an Excludes2 for separation anxiety disorder of childhood (F93.0).
Adjustment disorder codes also show up in other categories' notes. F32, the single-episode depression category, lists adjustment disorder (F43.2) as an Excludes2, and F41 lists transient adjustment reaction (F43.2) the same way. Excludes2, in the FY2027 guidelines' words, means a patient "may have both conditions at the same time", so both codes may be reported when both are documented diagnoses. It is permission, not a prompt to add a second code.
Grief deserves a note of its own, because the classification splits it. "Grief reaction" is an inclusion term under F43.2, the adjustment disorders. Prolonged grief disorder, complicated grief and persistent complex bereavement disorder are inclusion terms under F43.81. Which applies is the clinician's decision, and the note's wording is what lets the coder follow it.
F43.8 and F43.9: Other and Unspecified
F43.8 is a subcategory with two billable codes. F43.81 is prolonged grief disorder. F43.89 is other reactions to severe stress, and the F43.8 subcategory lists "other specified trauma and stressor-related disorder" as an inclusion term, which is the code a clinician's documentation of that DSM-5 label leads to.
F43.9, reaction to severe stress, unspecified, carries the inclusion terms "trauma and stressor-related disorder, NOS" and "unspecified trauma and stressor-related disorder". It is a billable code, and the right one when that is genuinely all the record supports.
What Changed for FY2027
Nothing in F43. The CMS FY2027 tabular addendum changes chapter 5, Mental, Behavioral and Neurodevelopmental disorders, in only two places: a note under F02 and the new code F64.A, gender identity disorder, in remission. The F43 codes, descriptors and inclusion terms carry over unchanged. If F43 claims started failing after October 1, look for incomplete codes or a stale template rather than the annual update. To look a code up yourself, the CDC's ICD-10-CM page links to the NCHS code browser.
Documentation That Supports an F43 Code
Clinical criteria belong to the clinician. What a biller or auditor needs is a straight line from the note to the claim, and in this family that line has a few specific points of failure.
- State the chronicity for PTSD. Without it, the only supportable code is F43.10.
- Name the adjustment disorder subtype. "Adjustment disorder with mixed anxiety and depressed mood" leads to F43.23; "adjustment disorder" alone leads to F43.20.
- Keep the diagnosis current. Adjustment disorders and acute stress reactions are often revised. When the clinician changes the diagnosis, the chart diagnosis should change too.
- Leave uncertainty off the claim. Section IV.H tells outpatient coders not to code diagnoses documented as "probable", "suspected", "rule out" or "working diagnosis", and to code the highest degree of certainty for that visit instead.
- Link every service line to a diagnosis. A psychotherapy line with no diagnosis pointer is a rejection waiting to happen.
- Record coexisting conditions that affect care. Section IV.J says to code all documented conditions that coexist and require or affect patient care.
How the Diagnosis Reaches the Claim in Ona
Ona is an AI-native, all-in-one practice management platform, with CRM, EHR and RCM on one patient record. For behavioral health practices, from solo trauma therapists to multi-location group practices, that means the code is chosen once and the claim reads it from the chart.
Choose the code. Add diagnosis searches by condition name or ICD-10 code and narrows through the hierarchy column by column, so F43 opens into F43.1 and then into F43.12. Each row shows whether it is billable, and Ona's help page on diagnoses states that a non-billable code cannot be added from the coded picker. That stops F43.1 and F43.2 from reaching a visit as if they were finished codes. Certainty can be recorded as Provisional or Differential on the chart; Section IV.H still decides what goes on the claim.
Write the note. AI charting drafts against DAP, BIRP or your own template from the recording, intake and chart, and every change Ona proposes waits for the clinician to keep or discard it. Signed notes lock, and corrections become amendments with a required reason.
Build the claim. Per Ona Insurance, the draft claim for each insured visit rebuilds as diagnoses, procedures and services change. The "Diagnosis codes on every line" billing rule requires a linked diagnosis on every claim line, and blocking errors stop submission until they are fixed. Eligibility runs at booking and again in the 48 hours before the visit.
Work the response. Claims go out through Ona Clearing House or your own Claim.MD account. Ona distinguishes a claim rejected by the clearinghouse from one denied by the payer, and a denied claim can be corrected as a linked replacement and resubmitted. From visit billing to superbill and claim covers the path, including superbills for patients seen out of network.
A saved diagnosis code cannot be edited in Ona. If the coded concept was wrong, archive it and add the right one, which preserves the record of what was coded at each visit.
What It Costs
Diagnosis coding, charting and claims are included in the seat. Per Ona's pricing page, practitioner seats are $130 per month and staff seats $45, with 10% off annually and a 14-day free trial with no credit card. An Ona Clearing House plan for insurance billing runs from $69 to $1,099 per month, each plan with unlimited providers and payer enrollments. Practices with five or more practitioners or several locations get custom pricing.
This coding guidance is general and reflects the FY2027 code set per CMS; payer rules vary, so confirm specific requirements with the payer.
Frequently asked questions
What is the ICD-10 code for PTSD?
PTSD is coded in F43.1 and needs a fifth character: F43.10 unspecified, F43.11 acute or F43.12 chronic. F43.1 on its own is a subcategory heading and is not a billable code.
What is the ICD-10 code for chronic PTSD?
F43.12, post-traumatic stress disorder, chronic. The ICD-10-CM tabular list does not define chronicity, so the code follows the clinician's documentation. If the note does not state acute or chronic, the supportable code is F43.10.
What is the ICD-10 code for adjustment disorder?
Adjustment disorders are coded F43.20 to F43.29. F43.20 is unspecified, and the others record the subtype: F43.21 depressed mood, F43.22 anxiety, F43.23 mixed anxiety and depressed mood, F43.24 disturbance of conduct, F43.25 mixed disturbance of emotions and conduct, and F43.29 other symptoms.
What is the ICD-10 code for acute stress reaction?
F43.0, acute stress reaction. It is a billable four-character code, and its inclusion terms include acute reaction to stress, acute crisis reaction, combat fatigue and psychic shock.
Is there an ICD-10 code for prolonged grief disorder?
Yes. F43.81, prolonged grief disorder, with complicated grief and persistent complex bereavement disorder as inclusion terms. A grief reaction, by contrast, is an inclusion term under the adjustment disorders in F43.2.
Did the PTSD and adjustment disorder codes change for FY2027?
No. The CMS FY2027 tabular addendum changes chapter 5 only with a note under F02 and a new code, F64.A. The F43 codes, descriptors and inclusion terms are unchanged.
Next step
Bring a trauma-focused psychotherapy claim to a 15-minute demo and follow F43.12 from the diagnosis picker to the draft claim and the billing rule that checks every line. Or start the 14-day free trial from the pricing page, no credit card needed.
Written by
Ona Health team