2026 ICD-10-CM Diagnosis Code Z40.9Encounter for prophylactic surgery, unspecified

ICD-10-CM Codes›Z00–Z99›Z40-Z53›Z40

ICD-10-CM Z40.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z40.9 is a billable ICD-10-CM diagnosis code for encounter for prophylactic surgery, unspecified. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Encounter for prophylactic or other procedures.

Code Identity

ICD-10-CM Code
Z40.9
Billable Status
Yes — Valid for Submission
Code Describes
Encounter for prophylactic surgery, unspecified
Short Description
Encounter for prophylactic surgery, unspecified
Same as the full description in the CMS dataset.
Parent Code
Z40
Encounter for prophylactic surgery

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ40-Z53Encounters for other specific health care
CategoryZ40Encounter for prophylactic surgery
This CodeZ40.9Encounter for prophylactic surgery, unspecified

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z40.9.

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.

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.

    • Prophylactic
      • surgery

Clinical ClassificationClinical

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

CCSR FAC004
Encounter for prophylactic or other procedures
Default principal diagnosis: inpatient No · outpatient Yes

Convert Z40.9 to ICD-9-CMHistory

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

ICD-9-CM
V50.8 Elective surgery NEC
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 Z40.9Overview

Is Z40.9 (Encounter for prophylactic surgery) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report encounter for prophylactic surgery, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z40.9 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because encounter for prophylactic surgery, unspecified 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 Z40.9?

Under the General Equivalence Mappings, encounter for prophylactic surgery, unspecified converts to ICD-9-CM V50.8 (elective surgery NEC). The mapping is approximate, so confirm the match fits the documentation.