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ICD-10-CM 2027 diagnosis code

X58.XXXAExposure to other specified factors, initial encounter

✓ Billable / specificRequires 7th character

X58.XXXA is a valid, billable ICD-10-CM code for exposure to other specified factors, 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 X58.XXXA

X58.XXXA is the ICD-10-CM diagnosis code for exposure to other specified factors, initial encounter. It belongs to category X58 (exposure to other specified factors), block X52-X58 (accidental exposure to other specified factors) 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 E928.8 (other accidents).

7th character

Ainitial encounter

Other encounter types for X58:

Notes that apply from higher levels

Instructions written at a parent level also apply to X58.XXXA.

Broader instructions also apply from Chapter 20: External causes of morbidity.

ICD-9-CM equivalent

Converter →
  • E928.8Other accidentsapproximate

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 X58.XXXA

Is X58.XXXA billable?

Yes. X58.XXXA 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 X58.XXXA 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 X58.XXXA be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict X58.XXXA as a principal diagnosis.

Is X58.XXXA a CC or MCC?

No. X58.XXXA is neither a CC nor an MCC under MS-DRG v44.0.

What is the ICD-9 code for X58.XXXA?

The CMS General Equivalence Mappings map X58.XXXA to ICD-9-CM E928.8.