Coding and coverage · ICD-10-CM

Y21 Drowning and submersion, undetermined intent

Not billable (header)Chapter 20

This code needs a 7th character (use X as a placeholder for missing characters).

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Codes under this one

  • Y21.0 Drowning and submersion while in bathtub, undetermined intentHeader
  • Y21.1 Drowning and submersion after fall into bathtub, undetermined intentHeader
  • Y21.2 Drowning and submersion while in swimming pool, undetermined intentHeader
  • Y21.3 Drowning and submersion after fall into swimming pool, undetermined intentHeader
  • Y21.4 Drowning and submersion in natural water, undetermined intentHeader
  • Y21.8 Other drowning and submersion, undetermined intentHeader
  • Y21.9 Unspecified drowning and submersion, undetermined intentHeader

Instructional notes

Chapter 20

Notes
  • This chapter permits the classification of environmental events and circumstances as the cause of injury, and other adverse effects. Where a code from this section is applicable, it is intended that it shall be used secondary to a code from another chapter of the Classification indicating the nature of the condition. Most often, the condition will be classifiable to Chapter 19, Injury, poisoning and certain other consequences of external causes (S00-T88). Other conditions that may be stated to be due to external causes are classified in Chapters I to XVIII. For these conditions, codes from Chapter 20 should be used to provide additional information as to the cause of the condition.

Section Y21-Y33

Inclusion terms
  • Undetermined intent is only for use when there is specific documentation in the record that the intent of the injury cannot be determined. If no such documentation is present, code to accidental (unintentional)

This code

7th charactersThe appropriate 7th character is to be added to each code from category Y21
  • A initial encounter
  • D subsequent encounter
  • S sequela

Chapter 20: External causes of morbidity · Y21-Y33 Event of undetermined intent (Y21-Y33)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.