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ICD-10-CM 2027 diagnosis code

W88.8XXAExposure to other ionizing radiation, initial encounter

✓ Billable / specificRequires 7th character

W88.8XXA is a valid, billable ICD-10-CM code for exposure to other ionizing radiation, initial encounter. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

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

About W88.8XXA

W88.8XXA is the ICD-10-CM diagnosis code for exposure to other ionizing radiation, initial encounter. It belongs to category W88 (exposure to ionizing radiation), block W85-W99 (exposure to electric current, radiation and extreme ambient air temperature and pressure) and chapter 20 (external causes of morbidity). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "A" means initial encounter: use it while the patient is receiving active treatment for the condition.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as E926.3 (exposure to x-rays and other electromagnetic ionizing radiation).

7th character

Ainitial encounter

Other encounter types for W88.8:

Notes that apply from higher levels

Instructions written at a parent level also apply to W88.8XXA.

› From W88 Exposure to ionizing radiation
Excludes1
  • exposure to sunlight (X32)

Broader instructions also apply from W85-W99 Exposure to electric current, radiation and extreme ambient air temperature and pressure and Chapter 20: External causes of morbidity.

ICD-9-CM equivalent

Converter →
  • E926.3Exposure to x-rays and other electromagnetic ionizing radiationapproximate

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 W88.8XXA

Is W88.8XXA billable?

Yes. W88.8XXA is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

What does the "A" at the end of W88.8XXA mean?

It is the 7th character for initial encounter. Per the official guidelines, use it while the patient is receiving active treatment for the condition.

Can W88.8XXA be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict W88.8XXA as a principal diagnosis.

Is W88.8XXA a CC or MCC?

No. W88.8XXA is neither a CC nor an MCC under MS-DRG v44.0.

What is the ICD-9 code for W88.8XXA?

The CMS General Equivalence Mappings map W88.8XXA to ICD-9-CM E926.3.