2026 ICD-10-CM Diagnosis Code T43.605SAdverse effect of unspecified psychostimulants, sequela

ICD-10-CM Codes›S00–T88›T36-T50›T43

ICD-10-CM T43.605S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T43.605S is a billable ICD-10-CM diagnosis code for adverse effect of unspecified psychostimulants, 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. Coders also document this condition as central stimulant adverse reaction. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Mental and substance use disorders; sequela; and Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T43.605S
Billable Status
Yes — Valid for Submission
Code Describes
Adverse effect of unspecified psychostimulants, sequela
Short Description
Adverse effect of unspecified psychostimulants, sequela
Same as the full description in the CMS dataset.
Parent Code
T43.605
Adverse effect of unspecified psychostimulants

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
CategoryT43Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified
This CodeT43.605SAdverse effect of unspecified psychostimulants, sequela

Code EditsBilling

Medicare Code Editor checks that affect claim validity for T43.605S.

Unacceptable principal diagnosis
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

T43.605S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Central stimulant adverse reaction

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 psychotropic drugs, not elsewhere classified (T43). 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 MBD034
Mental and substance use disorders; sequela
Default principal diagnosis: inpatient No · outpatient Yes
CCSR INJ075
Poisoning/toxic effect/adverse effects/underdosing, sequela
Default principal diagnosis: inpatient No · outpatient No

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
Cerebral stimulantsT43.601T43.602T43.603T43.604T43.605T43.606
Cerebral stimulants::psychotherapeuticT43.601T43.602T43.603T43.604T43.605T43.606
Cerebral stimulants::specified NECT43.601T43.602T43.603T43.604T43.605T43.606
PsychostimulantT43.601T43.602T43.603T43.604T43.605T43.606
Psychostimulant::amphetamineT43.601T43.602T43.603T43.604T43.605T43.606
Psychostimulant::caffeineT43.601T43.602T43.603T43.604T43.605T43.606
Psychostimulant::methylphenidateT43.601T43.602T43.603T43.604T43.605T43.606
Psychostimulant::specified NECT43.601T43.602T43.603T43.604T43.605T43.606
StimulantT43.601T43.602T43.603T43.604T43.605T43.606
Stimulant::central nervous system [See Also: Psychostimulant]T43.601T43.602T43.603T43.604T43.605T43.606
Stimulant::central nervous system [See Also: Psychostimulant]::analepticsT43.601T43.602T43.603T43.604T43.605T43.606
Stimulant::central nervous system [See Also: Psychostimulant]::opiate antagonistT43.601T43.602T43.603T43.604T43.605T43.606
Stimulant::central nervous system [See Also: Psychostimulant]::psychotherapeutic NEC [See Also: Psychotherapeutic drug]T43.601T43.602T43.603T43.604T43.605T43.606
Stimulant::central nervous system [See Also: Psychostimulant]::specified NECT43.601T43.602T43.603T43.604T43.605T43.606
Stimulant::respiratoryT43.601T43.602T43.603T43.604T43.605T43.606

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.

Convert T43.605S to ICD-9-CMHistory

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

ICD-9-CM
909.5 Lte efct advrs efct drug
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
E939.7 Adv eff psychostimulants
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

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 T43.605SOverview

Is T43.605S (Adverse effect of unspecified psychostimulants) a billable code?

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

What does the 7th character S in T43.605S mean?

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

What MS-DRG does T43.605S group to?

On inpatient claims, adverse effect of unspecified psychostimulants, 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 T43.605S be a principal diagnosis?

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

Is T43.605S 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 unspecified psychostimulants, 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.