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ICD-10-CM 2027 diagnosis code

X31.XXXSExposure to excessive natural cold, sequela

✓ Billable / specificPOA exemptRequires 7th character

X31.XXXS is a valid, billable ICD-10-CM code for exposure to excessive natural cold, sequela. 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 X31.XXXS

X31.XXXS is the ICD-10-CM diagnosis code for exposure to excessive natural cold, sequela. It belongs to category X31 (exposure to excessive natural cold), block X30-X39 (exposure to forces of nature) 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 "S" means sequela: use it for complications or conditions that arise as a direct result of the original condition.

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

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

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 E929.5 (late effects of accident due to natural and environmental factors).

7th character

Ssequela

Other encounter types for X31:

Notes that apply from higher levels

Instructions written at a parent level also apply to X31.XXXS.

› From X31 Exposure to excessive natural cold
Excludes1
  • cold of man-made origin (W93.-)
  • contact with or inhalation of dry ice (W93.-)
  • contact with or inhalation of liquefied gas (W93.-)

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

ICD-9-CM equivalent

Converter →
  • E929.5Late effects of accident due to natural and environmental factorsapproximate

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 X31.XXXS

Is X31.XXXS billable?

Yes. X31.XXXS is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

What does the "S" at the end of X31.XXXS mean?

It is the 7th character for sequela. Per the official guidelines, use it for complications or conditions that arise as a direct result of the original condition.

Can X31.XXXS be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict X31.XXXS as a principal diagnosis.

Is X31.XXXS a CC or MCC?

No. X31.XXXS is neither a CC nor an MCC under MS-DRG v44.0.

What is the ICD-9 code for X31.XXXS?

The CMS General Equivalence Mappings map X31.XXXS to ICD-9-CM E929.5.