2026 ICD-10-CM Diagnosis Code Z53.21Procedure and treatment not carried out due to patient leaving prior to being seen by health care provider

ICD-10-CM Codes›Z00–Z99›Z40-Z53›Z53

ICD-10-CM Z53.21
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z53.21 is a billable ICD-10-CM diagnosis code for procedure and treatment not carried out due to patient leaving prior to being seen by health care provider. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is not accepted as a principal diagnosis by the Medicare Code Editor. Coders also document this condition as left without being seen. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified status.

Code Identity

ICD-10-CM Code
Z53.21
Billable Status
Yes — Valid for Submission
Code Describes
Procedure and treatment not carried out due to patient leaving prior to being seen by health care provider
Short Description
Proc/trtmt not crd out d/t pt lv bef seen by hlth care prov
Parent Code
Z53.2
Procedure and treatment not carried out because of patient's decision for other and unspecified reasons

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ40-Z53Encounters for other specific health care
CategoryZ53Persons encountering health services for specific procedures and treatment, not carried out
This CodeZ53.21Procedure and treatment not carried out due to patient leaving prior to being seen by health care provider

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z53.21.

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.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Left without being seen
  • Patient walked out

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Procedure(surgical)
      • not done
        • because of
          • patient's decision
            • left without being seen
    • Refusal of
      • treatment (because of)
        • left without being seen

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR FAC025
Other specified status
Default principal diagnosis: inpatient No · outpatient Yes

Convert Z53.21 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V64.06 No vaccination-pt refuse
Approximate The match is approximate rather than exact.
ICD-9-CM
V64.2 No proc/patient decision
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z53.21Overview

Is Z53.21 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report procedure and treatment not carried out due to patient leaving prior to being seen by health care provider on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z53.21 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because procedure and treatment not carried out due to patient leaving prior to being seen by health care provider describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

What is the ICD-9 equivalent of Z53.21?

Under the General Equivalence Mappings, procedure and treatment not carried out due to patient leaving prior to being seen by health care provider converts to ICD-9-CM V64.06 (no vaccination-pt refuse) and V64.2 (no proc/patient decision). The mapping is approximate, so confirm the match fits the documentation.