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ICD-10-CM 2027 diagnosis code

Z77.4Contact with and (suspected) exposure to blast overpressure

Not billable — use a more specific codeNew for 2027

Z77.4 is a header code, so it can't be reported by itself. Choose one of the 4 more specific codes beneath it.

Code last changed in FY2027 (effective October 1, 2026). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About Z77.4

Z77.4 is the ICD-10-CM diagnosis code for contact with and (suspected) exposure to blast overpressure. It belongs to category Z77 (other contact with and (suspected) exposures hazardous to health), block Z77-Z99 (persons with potential health hazards related to family and personal history and certain conditions influencing health status) and chapter 21 (factors influencing health status and contact with health services). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.

Within Z77 (other contact with and (suspected) exposures hazardous to health), Z77.4 is specifically for contact with and (suspected) exposure to blast overpressure. Related codes cover contact with and (suspected) exposure to hazardous, chiefly nonmedicinal, chemicals (Z77.0), contact with and (suspected) exposure to environmental pollution and hazards in the physical environment (Z77.1), contact with and (suspected) exposure to other hazardous substances (Z77.2), contact with and (suspected) exposure to war theater (Z77.3) and other contact with and (suspected) exposures hazardous to health (Z77.9).

To report this condition, pick the subcode that matches the documentation: Z77.40 (overpressure), Z77.41 (overpressure), Z77.42 (overpressure) and Z77.49 (overpressure).

It was added in FY2027, effective October 1, 2026.

Specific codes under Z77.4

Notes that apply from higher levels

Instructions written at a parent level also apply to Z77.4.

› From Z77 Other contact with and (suspected) exposures hazardous to health
Includes
  • contact with and (suspected) exposures to potential hazards to health
Excludes2
  • contact with and (suspected) exposure to communicable diseases (Z20.-)
  • exposure to (parental) (environmental) tobacco smoke in the perinatal period (P96.81)
  • newborn affected by noxious substances transmitted via placenta or breast milk (P04.-)
  • occupational exposure to risk factors (Z57.-)
  • retained foreign body (Z18.-)
  • retained foreign body fully removed (Z87.821)
  • toxic effects of substances chiefly nonmedicinal as to source (T51-T65)

Broader instructions also apply from Z77-Z99 Persons with potential health hazards related to family and personal history and certain conditions influencing health status and Chapter 21: Factors influencing health status and contact with health services.

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
  • FY2027 (effective 10/1/2026): Added

Common questions about Z77.4

Is Z77.4 billable?

No. Z77.4 is a header code. Report one of its more specific subcodes instead.

Did Z77.4 change for 2027?

Yes. For FY2027 (effective October 1, 2026) it was added to the code set.