2024 ICD-10-CM Diagnosis Code Z48.21

Encounter for aftercare following heart transplant

ICD-10-CM Code:
Z48.21
ICD-10 Code for:
Encounter for aftercare following heart transplant
Is Billable?
Yes - Valid for Submission
Code Navigator:

Code Classification

  • Factors influencing health status and contact with health services
    (Z00–Z99)
    • Encounters for other specific health care
      (Z40-Z53)
      • Encounter for other postprocedural aftercare
        (Z48)

Z48.21 is a billable diagnosis code used to specify a medical diagnosis of encounter for aftercare following heart transplant. 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.

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).

Present on Admission (POA)

Z48.21 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 Z48.21 to ICD-9-CM

  • ICD-9-CM Code: V58.44 - Aftercare organ transplt
    Combination Flag - Multiple codes are needed to describe the source diagnosis code. Correct coding should be done based on contextual judgment.
  • ICD-9-CM Code: V42.1 - Heart transplant status
    Combination Flag - Multiple codes are needed to describe the source diagnosis code. Correct coding should be done based on contextual judgment.

Patient Education


Heart Transplantation

A heart transplant removes a damaged or diseased heart and replaces it with a healthy one. The healthy heart comes from a donor who has died. It is the last resort for people with heart failure when all other treatments have failed. The heart failure might have been caused by coronary heart disease, damaged heart valves or heart muscles, congenital heart defects, or viral infections of the heart.

Although heart transplant surgery is a life-saving measure, it has many risks. Careful monitoring, treatment, and regular medical care can prevent or help manage some of these risks.

After the surgery, most heart transplant patients can return to their normal levels of activity. However, fewer than 30% return to work for many different reasons.

NIH: National Heart, Lung, and Blood Institute


[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.