2026 ICD-10-CM Diagnosis Code T50.915SAdverse effect of multiple unspecified drugs, medicaments and biological substances, sequela

ICD-10-CM CodesS00–T88T36-T50T50

ICD-10-CM T50.915S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T50.915S is a billable ICD-10-CM diagnosis code for adverse effect of multiple unspecified drugs, medicaments and biological substances, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T50.915S
Billable Status
Yes — Valid for Submission
Code Describes
Adverse effect of multiple unspecified drugs, medicaments and biological substances, sequela
Short Description
Adverse effect of mult unsp drug/meds/biol subst, sequela
Parent Code
Adverse effect of multiple unspecified drugs, medicaments and biological substances

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT36-T50Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
CategoryT50Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances
This CodeT50.915SAdverse effect of multiple unspecified drugs, medicaments and biological substances, sequela

Code EditsBilling

Medicare Code Editor checks that affect claim validity for T50.915S.

There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)Billing

T50.915S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Coding GuidelinesGuidance

When coding an adverse effect of a drug that has been correctly prescribed and properly administered, assign the appropriate code for the nature of the adverse effect followed by the appropriate code for the adverse effect of the drug.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances (T50). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

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

CCSR INJ075
Poisoning/toxic effect/adverse effects/underdosing, sequela
Default principal diagnosis: inpatient No · outpatient Yes

Table of Drugs and ChemicalsClinical

Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.

SubstanceAccidentalSelf-harmAssaultUndeter­minedAdverse
Effect
Under­dosing
Multiple unspecified drugs, medicaments and biological substancesT50.911T50.912T50.913T50.914T50.915T50.916

Patient EducationClinical

Drug Reactions

Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions, such as drug interactions, side effects, and allergies.

The full article covers:

  • What is a drug interaction?
  • What are side effects?
  • What are drug allergies?
  • How can I stay safe when taking medicines?

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement T50.915S replaces the following previously assigned code(s):

  • T50.995S - Adverse effect of drug/meds/biol subst, sequela
FY 2020AddedAdded to the ICD-10-CM code setEffective October 1, 2019.
FY 2021–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T50.915SOverview

Is T50.915S a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report adverse effect of multiple unspecified drugs, medicaments and biological substances, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T50.915S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the adverse effect of multiple unspecified drugs, medicaments and biological substances itself has resolved, not the original event.

What MS-DRG does T50.915S group to?

On inpatient claims, adverse effect of multiple unspecified drugs, medicaments and biological substances, sequela maps to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

Can T50.915S be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because adverse effect of multiple unspecified drugs, medicaments and biological substances, sequela describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is T50.915S exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for adverse effect of multiple unspecified drugs, medicaments and biological substances, sequela on inpatient claims.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.