Skip to content
Dx

ICD-10-PCS 2027 procedure code

4A1002ZMonitoring of Central Nervous Conductivity, Open Approach

✓ Valid for 2027

Code unchanged since ICD-10-PCS took effect on October 1, 2015. Source: official FY2027 ICD-10-PCS release from CMS. Page updated September 29, 2026. About our data

About 4A1002Z

4A1002Z is the ICD-10-PCS code for a monitoring procedure on the central nervous using an open approach with conductivity. In ICD-10-PCS, monitoring means determining the level of a physiological or physical function repetitively over a period of time.

In plain terms, this corresponds to other nonoperative neurologic function tests, the ICD-9-CM procedure title it maps to (89.15).

The same procedure with a different approach is coded 4A10X2Z (external).

With a different device, use 4A1004Z (electrical activity) and 4A100BZ (pressure).

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

It has been valid since ICD-10-PCS took effect on October 1, 2015.

What each character means

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

Determining the level of a physiological or physical function repetitively over a period of time

4. Body System
0Central Nervous
5. Approach
0Open

Cutting through the skin or mucous membrane and any other body layers necessary to expose the site of the procedure

6. Function / Device
2Conductivity
7. Qualifier
ZNo Qualifier

Other versions of this procedure

Different approach

ICD-9-CM equivalent

Converter →
  • 89.15Other nonoperative neurologic function testsapproximate

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
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about 4A1002Z

Is 4A1002Z a valid ICD-10-PCS code for 2027?

Yes. 4A1002Z is valid for inpatient procedures from October 1, 2026 through September 30, 2027.

What is the ICD-9 procedure code for 4A1002Z?

The CMS GEMs map 4A1002Z to ICD-9-CM 89.15 (Other nonoperative neurologic function tests).