2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 951. 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.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Z40.9: its own notes plus those printed at Z40, block Z40-Z53, and Chapter 21. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Z40 Encounter for prophylactic surgery applies to 9 codes
  • organ donations (Z52.-)
  • therapeutic organ removal-code to condition

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block Z40-Z53 Encounters for other specific health care applies to 164 codes
  • follow-up examination for medical surveillance after treatment (Z08-Z09)

Notes

General instructions on how these codes are used.

From Chapter 21 (Z00-Z99) Factors influencing health status and contact with health services applies to 1,425 codes
  • Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
  • (a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
  • (b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name Z40.9, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming Z40.9: they are not reported together with it, unless the two conditions are unrelated.

  • Z29 Encounter for other prophylactic measures
    prophylactic surgery (Z40.-) names Z40.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Z40.9Overview

What is the ICD-10 code for encounter for prophylactic surgery, unspecified?

The ICD-10-CM code for encounter for prophylactic surgery, unspecified is Z40.9 (sometimes written as Z409). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does Z40.9 group to?

On inpatient claims, encounter for prophylactic surgery, unspecified maps to MS-DRG 951 (other Factors Influencing Health Status), which carries a relative weight of 0.5574. Higher weights mean higher Medicare reimbursement.

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.

Can Z40.9 be reported with a code from Z52?

Not as a rule. The Excludes1 note at Z40, which applies to Z40.9, lists "organ donations (Z52.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).