2024 ICD-10-CM Diagnosis Code Z86.51

Personal history of combat and operational stress reaction

ICD-10-CM Code:
Z86.51
ICD-10 Code for:
Personal history of combat and operational stress reaction
Is Billable?
Yes - Valid for Submission
Code Navigator:

Code Classification

  • Factors influencing health status and contact with health services
    (Z00–Z99)
    • Persons with potential health hazards related to family and personal history and certain conditions influencing health status
      (Z77-Z99)
      • Personal history of certain other diseases
        (Z86)

Z86.51 is a billable diagnosis code used to specify a medical diagnosis of personal history of combat and operational stress reaction. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024. The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.

The code Z86.51 is applicable to adult patients aged 15 through 124 years inclusive. It is clinically and virtually impossible to use this code on a patient outside the stated age range.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • History of combat and operational stress reaction

Clinical Classification

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10-CM Code Edits are applicable to this code:

  • Adult diagnoses - The Medicare Code Editor detects inconsistencies in adult cases by checking a patient's age and any diagnosis on the patient's record. The adult code edits apply to patients age range is 15–124 years inclusive (e.g., senile delirium, mature cataract).
  • Unacceptable principal diagnosis - There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)

Z86.51 is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here.

CMS POA Indicator Options and Definitions

POA IndicatorReason for CodeCMS will pay the CC/MCC DRG?
YDiagnosis was present at time of inpatient admission.YES
NDiagnosis was not present at time of inpatient admission.NO
UDocumentation insufficient to determine if the condition was present at the time of inpatient admission.NO
WClinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.YES
1Unreported/Not used - Exempt from POA reporting. NO

Convert Z86.51 to ICD-9-CM

  • ICD-9-CM Code: V11.4 - Hx combat/stress reactn

Patient Education


Post-Traumatic Stress Disorder

What is post-traumatic stress disorder (PTSD)?

Post-traumatic stress disorder (PTSD) is a mental health disorder that some people develop after they experience or see a traumatic event. The traumatic event may be life-threatening, such as combat, a natural disaster, a car accident, or sexual assault. But sometimes the event is not necessarily a dangerous one. For example, the sudden, unexpected death of a loved one can also cause PTSD.

It's normal to feel afraid during and after a traumatic situation. The fear triggers a "fight-or-flight" response. This is your body's way of helping to protect itself from possible harm. It causes changes in your body such as the release of certain hormones and increases in alertness, blood pressure, heart rate, and breathing.

In time, most people recover from this naturally. But people with PTSD don't feel better. They feel stressed and frightened long after the trauma is over. In some cases, the PTSD symptoms may start later on. They might also come and go over time.

What causes post-traumatic stress disorder (PTSD)?

Researchers don't know why some people get PTSD and others don't. Genetics, neurobiology, risk factors, and personal factors may affect whether you get PTSD after a traumatic event.

Who is at risk for post-traumatic stress disorder (PTSD)?

You can develop PTSD at any age. Many risk factors play a part in whether you will develop PTSD. They include:

  • Your sex; women are more likely to develop PTSD
  • Having had trauma in childhood
  • Feeling horror, helplessness, or extreme fear
  • Going through a traumatic event that lasts a long time
  • Having little or no social support after the event
  • Dealing with extra stress after the event, such as loss of a loved one, pain and injury, or loss of a job or home
  • Having a history of mental illness or substance use

What are the symptoms of post-traumatic stress disorder (PTSD)?

There are four types of PTSD symptoms, but they may not be the same for everyone. Each person experiences symptoms in their own way. The types are:

  • Re-experiencing symptoms, where something reminds you of the trauma and you feel that fear again. Examples include
    • Flashbacks, which cause you to feel like you are going through the event again
    • Nightmares
    • Frightening thoughts
  • Avoidance symptoms, where you try to avoid situations or people that trigger memories of the traumatic event. This may cause you to
    • Stay away from places, events, or objects that are reminders of the traumatic experience. For example, if you were in a car accident, you might stop driving.
    • Avoiding thoughts or feelings related to the traumatic event. For example, you might try to stay very busy to try to avoid thinking about what happened.
  • Arousal and reactivity symptoms, which may cause you to be jittery or be on the lookout for danger. They include
    • Being easily startled
    • Feeling tense or "on edge"
    • Having difficulty sleeping
    • Having angry outbursts
  • Cognition and mood symptoms, which are negative changes in beliefs and feelings. They include
    • Trouble remembering important things about the traumatic event
    • Negative thoughts about yourself or the world
    • Feeling blame and guilt
    • No longer being interested in things you enjoyed
    • Trouble concentrating

The symptoms usually start soon after the traumatic event. But sometimes they may not appear until months or years later. They also may come and go over many years.

If your symptoms last longer than four weeks, cause you great distress, or interfere with your work or home life, you might have PTSD.

How is post-traumatic stress disorder (PTSD) diagnosed?

A health care provider who has experience helping people with mental illnesses can diagnose PTSD. The provider will do a mental health screening and may also do a physical exam. To get a diagnosis of PTSD, you must have all of these symptoms for at least one month:

  • At least one re-experiencing symptom
  • At least one avoidance symptom
  • At least two arousal and reactivity symptoms
  • At least two cognition and mood symptoms

What are the treatments for post-traumatic stress disorder (PTSD)?

The main treatments for PTSD are talk therapy, medicines, or both. PTSD affects people differently, so a treatment that works for one person may not work for another. If you have PTSD, you need to work with a mental health professional to find the best treatment for your symptoms.:

  • Talk therapy, or psychotherapy, which can teach you about your symptoms. You will learn how to identify what triggers them and how to manage them. There are different types of talk therapy for PTSD.
  • Medicines can help with the symptoms of PTSD. Antidepressants may help control symptoms such as sadness, worry, anger, and feeling numb inside. Other medicines can help with sleep problems and nightmares.

Can post-traumatic stress disorder (PTSD) be prevented?

There are certain factors that can help reduce the risk of developing PTSD. These are known as resilience factors, and they include:

  • Seeking out support from other people, such as friends, family, or a support group
  • Learning to feel good about your actions in the face of danger
  • Having a coping strategy or a way of getting through the bad event and learning from it
  • Being able to act and respond effectively despite feeling fear

Researchers are studying the importance of the resilience and risk factors for PTSD. They are also studying how genetics and neurobiology can affect the risk of PTSD. With more research, someday it may be possible to predict who is likely to develop PTSD. This could also help in finding ways to prevent it.

NIH: National Institute of Mental Health


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.