Post-traumatic stress disorder can be straightforward to recognize clinically, but the claim does not always tell the same story as the medical record.
A provider may document PTSD, spend the appropriate amount of time evaluating or treating the patient, and still see a claim delayed because the diagnosis lacks the specificity supported by the note, the psychotherapy code does not match the documented time, or an authorization requirement was missed.
The ICD-10 code for PTSD most commonly used when the condition is not further specified is F43.10 — Post-traumatic stress disorder, unspecified. However, F43.10 is not the only PTSD diagnosis code available. Providers should select the code that most accurately reflects the diagnosis documented for that encounter.
This guide explains F43.10, related PTSD ICD-10 codes, commonly reported CPT codes, modifiers, documentation considerations, and several denial and remark codes that may appear when PTSD-related behavioral health claims are processed.
What Is the ICD-10 Code for PTSD?
The ICD-10-CM category used for post-traumatic stress disorder is F43.1-.
For billing purposes, three codes within this category are especially important:
| ICD-10-CM Code | Diagnosis |
|---|---|
| F43.10 | Post-traumatic stress disorder, unspecified |
| F43.11 | Post-traumatic stress disorder, acute |
| F43.12 | Post-traumatic stress disorder, chronic |
CMS Medicare coverage materials list all three diagnosis codes within psychiatry and psychology services.
The distinction matters.
If the medical record simply establishes PTSD without documenting whether it is acute or chronic, F43.10 may be appropriate. When the treating provider clearly documents an acute or chronic form, the corresponding more specific code should generally be considered instead.
The diagnosis code should follow the clinical documentation. A claim should not be made more specific simply to improve reimbursement.
What Does F43.10 Mean?
F43.10 identifies post-traumatic stress disorder, unspecified.
In everyday billing terms, the code tells the payer that PTSD has been diagnosed, but the available documentation does not identify the condition as acute or chronic.
That makes F43.10 different from an uncertain or suspected diagnosis. It still represents PTSD. The word “unspecified” refers to the level of detail represented by the ICD-10-CM code.
For example, a patient may be evaluated following a history of traumatic exposure and meet the provider’s criteria for PTSD. If the documentation establishes PTSD but does not further classify the condition, F43.10 may accurately reflect the record.
On the other hand, if the note specifically supports chronic PTSD, continuing to submit F43.10 instead of F43.12 could result in coding that does not fully reflect the provider’s documentation.
CMS currently recognizes F43.10, F43.11, and F43.12 within applicable psychiatry and psychology billing guidance.
F43.10 vs. F43.11 vs. F43.12
The three codes can look almost interchangeable on a claim, but they communicate different information.
F43.10 — PTSD, Unspecified
Use F43.10 when PTSD is documented but the medical record does not support the additional acute or chronic classification.
A note that simply states:
Post-traumatic stress disorder
may lead to F43.10 when no additional specificity appears elsewhere in the record.
F43.11 — PTSD, Acute
F43.11 represents post-traumatic stress disorder, acute.
This code should be supported by documentation that establishes PTSD and identifies the condition as acute.
F43.12 — PTSD, Chronic
F43.12 represents post-traumatic stress disorder, chronic.
When the clinician has specifically documented chronic PTSD, F43.12 gives the claim greater diagnostic specificity than F43.10.
A practical rule for providers is simple: do not choose between these codes based only on the claim form. Choose from the clinical record.
Related ICD-10-CM Codes Providers May Encounter
Not every trauma-related mental health presentation should automatically be coded as PTSD.
Depending on the clinical findings, other diagnoses within the stress- and anxiety-related categories may be relevant.
| ICD-10-CM Code | Description |
|---|---|
| F43.0 | Acute stress reaction |
| F43.20 | Adjustment disorder, unspecified |
| 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 |
| F43.89 | Other reactions to severe stress |
| F43.9 | Reaction to severe stress, unspecified |
| F41.1 | Generalized anxiety disorder |
| F41.9 | Anxiety disorder, unspecified |
CMS psychiatry coding materials include these conditions alongside PTSD-related diagnosis codes.
Providers should avoid selecting a PTSD diagnosis merely because the patient reports trauma, anxiety, nightmares, or distress. The diagnosis entered on the claim should reflect the condition established and documented by the treating clinician.
DX Coding for PTSD Claims
On a professional claim, F43.10 functions as the diagnosis or DX code supporting the service being reported.
The CPT code answers:
What service did the provider perform?
The diagnosis code answers:
Why was that service medically necessary?
For example:
DX: F43.10
Procedure: 90834
In this situation, the claim indicates that psychotherapy was provided in connection with the patient’s documented PTSD.
A diagnosis alone, however, does not guarantee payment. The CPT service, provider type, treatment documentation, patient eligibility, authorization requirements, frequency rules, and payer coverage policy must also line up.
That is why behavioral health claims often require more attention than simply pairing a mental health diagnosis with a psychotherapy code.
Common CPT Codes Used When Treating PTSD
There is no single CPT code that means “PTSD treatment.” CPT coding describes the service furnished rather than the diagnosis itself.
CMS identifies several commonly used mental health procedure codes.
Psychiatric Diagnostic Evaluation
90791 — Psychiatric diagnostic evaluation
This code may be appropriate for a psychiatric diagnostic assessment that does not include medical services.
90792 — Psychiatric diagnostic evaluation with medical services
This may be reported by an appropriately qualified professional when the psychiatric evaluation includes medical services.
The documentation should support the nature and scope of the evaluation performed.
Individual Psychotherapy
Common psychotherapy codes include:
| CPT Code | Service |
|---|---|
| 90832 | Individual psychotherapy, approximately 30 minutes |
| 90834 | Individual psychotherapy, approximately 45 minutes |
| 90837 | Individual psychotherapy, approximately 60 minutes |
CMS includes these among commonly used mental-health-related CPT codes.
The exact CPT selection must follow the applicable CPT time requirements and the time actually supported by the record. A provider should not routinely bill 90837 simply because an appointment was scheduled for an hour.
Documentation and billable psychotherapy time need to agree.
Psychotherapy With an E/M Service
When psychotherapy is performed along with a separately reportable evaluation and management service by a provider eligible to bill E/M services, psychotherapy add-on codes may come into play.
Common examples include:
90833 — psychotherapy add-on associated with an E/M service
90836 — psychotherapy add-on associated with an E/M service
90838 — psychotherapy add-on associated with an E/M service
CMS recognizes these codes among commonly billed mental health services.
This area deserves careful documentation.
The medical record should make it possible to understand the work represented by the E/M service and the psychotherapy service. Simply listing medication management and psychotherapy in the assessment may not be enough to defend both services if the payer requests records.
PTSD Crisis Psychotherapy Codes
A PTSD patient may occasionally present during a psychiatric crisis requiring urgent assessment and psychotherapy.
CMS identifies:
90839 — Psychotherapy for crisis, first 60 minutes
90840 — Each additional 30 minutes
90840 is reported with 90839 when the additional time requirements are met.
CMS also notes that psychotherapy-for-crisis codes should not simply be billed together with regular psychotherapy or psychiatric diagnostic codes for the same crisis service.
Providers should document the crisis circumstances, clinical intervention, time, risk assessment, treatment decisions, and disposition clearly.
Other Behavioral Health CPT Codes That May Appear
Depending on what actually occurs during the encounter, providers may also encounter codes such as:
90785 — interactive complexity add-on
90853 — group psychotherapy
96127 — brief emotional or behavioral assessment when applicable and supported
These codes should not automatically be added to every PTSD visit. Each represents a specific service with its own requirements.
For instance, having a patient complete a questionnaire does not mean every encounter automatically supports every behavioral assessment code. The service must satisfy applicable coding and payer requirements.
Modifiers That May Matter for PTSD Billing
Modifiers are another area where behavioral health claims can go wrong.
There is no “PTSD modifier.” The modifier depends on how and where the service was performed and the payer’s billing instructions.
Modifier 95
Modifier 95 is associated with synchronous telemedicine using real-time audio and video when required under the applicable billing policy.
Telehealth billing has become particularly relevant in behavioral health because psychotherapy and psychiatric services are frequently furnished remotely.
CMS instructs professional claims to use appropriate telehealth place-of-service coding, including:
POS 02 — telehealth provided other than in the patient’s home
POS 10 — telehealth provided in the patient’s home.
Do not assume that modifier 95 must appear on every telehealth claim. Requirements can differ according to payer, provider type, facility type, service, and current policy.
Modifier 93
Modifier 93 may apply to qualifying synchronous audio-only telemedicine services when permitted by the payer and service rules.
For example, CMS has specifically instructed RHCs and FQHCs that beginning October 1, 2026, appropriate telehealth modifiers include 93 for qualifying real-time audio-only services and 95 for qualifying real-time audio/video services.
That policy should not be generalized to every payer or billing situation. Verify the patient’s plan before submitting the claim.
Modifier 25
Modifier 25 can become relevant when a significant, separately identifiable E/M service is performed on the same day as another procedure or service.
It should never be attached automatically just because two codes appear on the claim.
The medical record must support that the E/M work is separately identifiable, and payer editing rules should be reviewed before billing.
Documentation Providers Should Have Before Billing F43.10
Good PTSD documentation does more than establish the patient’s diagnosis. It connects the condition to the care being furnished.
A strong record generally makes clear why the patient is being seen, what symptoms or clinical issues are being addressed, the provider’s assessment, the treatment performed, and the plan moving forward.
For psychotherapy services, the record should also support the billed service and its applicable time requirement.
Providers should pay particular attention to:
the PTSD diagnosis and appropriate specificity;
the patient’s current symptoms and functional concerns;
relevant assessment findings;
medical necessity for treatment;
the psychotherapy intervention or other service furnished;
time when required by the CPT code;
treatment progress and response;
medication evaluation when applicable;
risk or safety assessment when clinically appropriate;
and the plan for continued treatment.
The point is not to create longer notes simply for billing.
The goal is for the medical record to show what happened during the encounter and why the reported service was reasonable and necessary.
Why PTSD Claims Get Denied
Behavioral health denials are not always caused by the PTSD diagnosis itself.
A perfectly valid F43.10 diagnosis can still sit on a denied claim.
Medical Necessity Problems
One possible denial is CARC 50, which X12 defines as a noncovered service because the payer does not consider it medically necessary.
For a PTSD-related psychotherapy claim, providers should review whether the documentation adequately supports the service, frequency, duration, and ongoing treatment need.
If a payer requested records, simply resubmitting the same claim without reviewing the documentation usually does not address the underlying problem.
Noncovered Service
CARC 96 indicates a noncovered charge. X12 notes that this code is accompanied by an additional remark code explaining the adjustment.
The next step is to read the accompanying RARC rather than treating “96” as the complete explanation.
The service could be excluded under the patient’s benefits, performed by an ineligible provider, subject to another coverage rule, or missing something required for adjudication.
Missing Authorization
Behavioral health plans sometimes require authorization for particular levels, quantities, or types of mental health treatment.
CARC 197 means required precertification, authorization, notification, or pretreatment approval was absent.
Before providing ongoing psychotherapy, practices should know whether the patient’s plan requires authorization and whether there is a visit limit or authorization period.
Benefit Exclusion
CARC 204 means the service, equipment, or drug is not covered under the patient’s current benefit plan.
This is different from a diagnosis coding problem. Checking eligibility and behavioral health benefits before treatment can help identify these restrictions earlier.
Missing or Invalid Claim Information
CARC 16 indicates that the claim lacks information or contains a submission or billing error. X12 requires an accompanying remark code to provide additional detail.
The remark code is therefore critical.
The problem might involve provider information, documentation, claim data, or another element entirely.
Remark Codes Providers May See
A Remittance Advice Remark Code, or RARC, adds detail to the payer’s adjustment.
Providers should read the CARC and RARC together rather than addressing only one.
Some examples that can be relevant to behavioral health claims include:
RARC N42 — Missing Mental Health Assessment
X12 lists N42 as “Missing mental health assessment.”
If this appears on a PTSD-related claim, determine exactly what assessment or documentation the payer expected and follow the payer’s correction or appeal process.
RARC N393 — Missing Progress Notes/Report
N393 indicates that required progress notes or a report are missing.
This can occur during medical review when the payer needs documentation to support the service billed.
RARC N394 — Incomplete or Invalid Progress Notes/Report
N394 signals that progress-note information supplied was incomplete or invalid.
Sending additional records without first understanding what was missing may simply lead to another unfavorable determination.
RARC N290 — Rendering Provider Identifier Problem
N290 identifies a missing, incomplete, or invalid rendering provider primary identifier.
This points toward claim or enrollment data rather than the PTSD diagnosis.
These examples are not a fixed list of “PTSD denial codes.” A payer can return many different combinations depending on the actual reason for adjustment.
A Practical PTSD Claim Example
Consider a behavioral health practice treating an established patient with documented chronic PTSD.
The record supports:
Diagnosis: chronic PTSD
DX: F43.12
Service: individual psychotherapy
Documented psychotherapy time: supports the applicable psychotherapy CPT code
Location: patient at home through qualifying telehealth
POS: 10
Modifier: applied according to the payer’s telehealth instructions
The important part is that all pieces agree.
If the physician documents chronic PTSD but submits F43.10, the diagnosis is less specific than the record.
If 90837 is reported but the documented psychotherapy time does not support it, the procedure coding may be questioned.
If telehealth information is inconsistent, the payer may reject or deny the service even though the diagnosis and psychotherapy itself were appropriate.
Small discrepancies can create large administrative problems when they repeat across dozens of behavioral health visits.
F43.10 Coding Mistakes Worth Watching
One common issue is treating F43.10 as the universal PTSD code.
It is not.
It is specifically the unspecified PTSD code.
Another frequent problem is changing the diagnosis code simply because a claim denied. A denial does not automatically mean F43.10 is wrong. Providers should first determine whether the payer objected to diagnosis specificity, medical necessity, authorization, eligibility, procedure coding, provider enrollment, telehealth reporting, documentation, or something else.
Time-based psychotherapy coding deserves the same attention. Selecting the CPT code based on the scheduled appointment length rather than the supported service time can create unnecessary exposure during payer review.
Finally, do not copy diagnoses forward indefinitely without ensuring they still reflect the provider’s current assessment.
Improving PTSD Billing Without Making Documentation Harder
Providers generally do not need more complicated documentation. They need documentation that consistently supports what is being billed.
A useful workflow starts with the clinical record.
The diagnosis should be documented at the level of specificity known to the clinician. The CPT code should represent the service actually furnished. Time should be recorded whenever the reported service depends on time. Telehealth information should be captured when relevant. Authorization and eligibility should be checked according to the patient’s plan.
Once payment returns, denials should be worked from the actual remittance codes instead of relying on broad labels such as “medical necessity denial.”
For practices that continue to see recurring behavioral health claim issues, NYC Medical Billing can help review coding, eligibility, authorization, claim submission, payment posting, and denial patterns while allowing providers to remain focused on patient care.
ICD-10 Code Updates and Payer Policies
ICD-10-CM should always be checked against the code set applicable to the date of service.
CMS states that the current FY 2026 ICD-10-CM files apply to encounters through September 30, 2026, while FY 2027 ICD-10-CM codes become effective October 1, 2026.
Providers should also remember that correct ICD-10 and CPT coding does not override payer-specific coverage requirements.
Commercial insurers, Medicare Advantage plans, Medicaid programs, and other payers may have different requirements involving authorization, behavioral health networks, telehealth, visit limits, credentialing, and documentation.
Checking those requirements before repeated treatment is usually easier than trying to reverse a series of denials afterward.
Final Thoughts
F43.10 is the ICD-10 code for post-traumatic stress disorder, unspecified, but correct PTSD billing involves much more than entering one diagnosis code.
Providers need to distinguish F43.10 from F43.11 and F43.12 when the documentation supports additional specificity. The psychotherapy or psychiatric CPT code must accurately represent the service delivered, time-based codes need appropriate time documentation, and telehealth services need to follow current payer requirements.
When a claim does deny, the CARC and RARC should guide the response. A medical necessity denial requires a different approach than missing authorization, invalid provider information, or incomplete documentation.
A consistent process around diagnosis coding, psychotherapy documentation, eligibility, authorization, and remittance review can prevent many avoidable behavioral health billing problems. Practices that need additional support with these workflows can work with NYC Medical Billing to strengthen claim accuracy, denial follow-up, and revenue cycle performance without adding more administrative work to the provider’s day.
Frequently Asked Questions About the ICD-10 Code for PTSD
What is the ICD-10 code for PTSD?
The ICD-10-CM code for unspecified post-traumatic stress disorder is F43.10.
What is the difference between F43.10 and F43.12?
F43.10 represents unspecified PTSD. F43.12 represents chronic PTSD. The code selected should reflect the provider’s documented diagnosis.
What is F43.11?
F43.11 represents acute post-traumatic stress disorder.
Is F43.10 a billable diagnosis code?
F43.10 is used as a specific ICD-10-CM diagnosis code for post-traumatic stress disorder, unspecified. CMS includes it among covered diagnosis codes within applicable psychiatry and psychology billing guidance. Coverage of an individual service still depends on the procedure, medical necessity, payer policy, provider eligibility, and other claim requirements.
What CPT code should be used with F43.10?
There is no one CPT code required for F43.10. The procedure code depends on the service provided.
Examples include 90791 for psychiatric diagnostic evaluation and 90832, 90834, or 90837 for applicable individual psychotherapy services.
Can F43.10 be billed with telehealth psychotherapy?
Potentially, yes, when the psychotherapy service qualifies for telehealth coverage and all payer requirements are met. For Medicare professional claims, CMS identifies POS 02 and POS 10 for telehealth depending on the patient’s location.
Why would a PTSD psychotherapy claim be denied?
The reason could involve medical necessity, coverage, authorization, incorrect procedure coding, provider eligibility, documentation, telehealth reporting, benefit limits, or missing claim information. Providers should read the CARC and RARC on the remittance before deciding how to correct or appeal the claim.