Y63.6 Underdosing and nonadministration of necessary drug, medicament or biological substance

The ICD-10-CM code for Underdosing and nonadministration of necessary drug, medicament or biological substance is Y63.6 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

20: External causes of morbidity (V00-Y99)

Section

Y62-Y69: Misadventures to patients during surgical and medical care (Y62-Y69)

Category Y63

10 codes (9 billable)

FY2026 Status

Stable since FY2024

U.S. Hospital Utilization

• An estimated 2,470 U.S. inpatient stays in 2023 included Y63.6 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Use Z91.12-/Z91.13-/Z91.14-/Z91.A4- or Y63.6-Y63.9 with underdosing

Noncompliance (Z91.12-, Z91.13-, Z91.14- and Z91.A4-) or complication of care (Y63.6-Y63.9) codes are to be used with an underdosing code to indicate intent, if known.

Used with any code in range A00.0-T88.9, Z00-Z99

1) Used with any code in the range of A00.0-T88.9, Z00-Z99 An external cause code may be used with any code in the range of A00.0-T88.9, Z00-Z99, classification that represents a health condition due to an external cause. Though they are most applicable to injuries, they are also valid for use with such things as infections or diseases due to an external source, and other health conditions, such as a heart attack that occurs during strenuous physical activity.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)

Cite This Page

Reference Y63.6 with the canonical source and edition:

Y63.6 — Underdosing and nonadministration of necessary drug, medicament or biological substance. ICD-10 Coding Pro (ICD-10-CM FY2026). https://icd10codingpro.com/codes/Y63.6

Canonical URL: https://icd10codingpro.com/codes/Y63.6