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ICD-10-PCS 2027 procedure code

4A0074ZMeasurement of Central Nervous Electrical Activity, Via Natural or Artificial Opening

✓ Valid for 2027

Short description: Measurement of Central Nervous Electr Activity, Via Opening

Code last changed in FY2018 (effective October 1, 2017). Source: official FY2027 ICD-10-PCS release from CMS. Page updated September 29, 2026. About our data

About 4A0074Z

4A0074Z is the ICD-10-PCS code for a measurement procedure on the central nervous using a via natural or artificial opening approach with electrical activity. In ICD-10-PCS, measurement means determining the level of a physiological or physical function at a point in time.

In plain terms, this corresponds to electroencephalogram, the ICD-9-CM procedure title it maps to (89.14).

For a different body part, codes include 4A0174Z (peripheral nervous), 4A0274Z (cardiac), 4A0H74Z (products of conception, cardiac) and 4A0J74Z (products of conception, nervous).

The same procedure with a different approach is coded 4A0004Z (open), 4A0034Z (percutaneous), 4A0084Z (via natural or artificial opening endoscopic) and 4A00X4Z (external).

It doesn't appear in the MS-DRG procedure index, so on its own it doesn't change the DRG assignment.

It was added in FY2018, effective October 1, 2017.

What each character means

1. Section
4Measurement and Monitoring
2. Body System
APhysiological Systems
3. Operation
0Measurement

Determining the level of a physiological or physical function at a point in time

4. Body System
0Central Nervous
5. Approach
7Via Natural or Artificial Opening

Entry of instrumentation through a natural or artificial external opening to reach the site of the procedure

6. Function / Device
4Electrical Activity
7. Qualifier
ZNo Qualifier

Other versions of this procedure

ICD-9-CM equivalent

Converter →
  • 89.14Electroencephalogramapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2018 (effective 10/1/2017): Added
  • No changes since FY2018.

Common questions about 4A0074Z

Is 4A0074Z a valid ICD-10-PCS code for 2027?

Yes. 4A0074Z is valid for inpatient procedures from October 1, 2026 through September 30, 2027.

What is the ICD-9 procedure code for 4A0074Z?

The CMS GEMs map 4A0074Z to ICD-9-CM 89.14 (Electroencephalogram).