2026 ICD-10-CM Diagnosis Code Y66Nonadministration of surgical and medical care

ICD-10-CM CodesV01–Y99Y62-Y84Y66

ICD-10-CM Y66
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Y66 is a billable ICD-10-CM diagnosis code for nonadministration of surgical and medical care. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: complications of medical and surgical care, initial encounter.

Code Identity

ICD-10-CM Code
Y66
Billable Status
Yes — Valid for Submission
Code Describes
Nonadministration of surgical and medical care
Chapter
Y62-Y84
Complications of medical and surgical care

Code Classification

ChapterV01–Y99External causes of morbidity and mortality
SectionY62-Y84Complications of medical and surgical care
CategoryY66Nonadministration of surgical and medical care
This CodeY66Nonadministration of surgical and medical care

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Premature cessation of surgical and medical care

Type 1 Excludes

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR EXT025
External cause codes: complications of medical and surgical care, initial encounter
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Patient Safety

You can help prevent medical errors by being an active member of your health care team. Research shows that patients who are more involved with their care tend to get better results. To reduce the risk of medical errors, you can:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert Y66 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
E876.8 Medical misadventure NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Y66Overview

Is Y66 (Nonadministration of surgical and medical care) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report nonadministration of surgical and medical care on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of Y66?

Under the General Equivalence Mappings, nonadministration of surgical and medical care converts to ICD-9-CM E876.8 (medical misadventure NEC). The mapping is approximate, so confirm the match fits the documentation.