2026 ICD-10-CM Diagnosis Code T43.603SPoisoning by unspecified psychostimulants, assault, sequela

ICD-10-CM T43.603S

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

T43.603S is a billable ICD-10-CM diagnosis code for poisoning by unspecified psychostimulants, assault, 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 exempt from POA reporting. 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

T43.603S

Billable Status

Yes — Valid for Submission

Code Describes

Poisoning by unspecified psychostimulants, assault, sequela

Short Description

Poisoning by unspecified psychostimulants, assault, sequela

Same as the full description in the CMS dataset.

Parent Code

T43.603

Poisoning by unspecified psychostimulants, assault

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 CodeT43.603SPoisoning by unspecified psychostimulants, assault, sequela

Present on Admission (POA)Billing

T43.603S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Coding GuidelinesGuidance

When coding a poisoning or reaction to the improper use of a medication (e.g., overdose, wrong substance given or taken in error, wrong route of administration), first assign the appropriate code from categories T36-T50. The poisoning codes have an associated intent as their 5th or 6th character (accidental, intentional self-harm, assault and undetermined). If the intent of the poisoning is unknown or unspecified, code the intent as accidental intent. The undetermined intent is only for use if the documentation in the record specifies that the intent cannot be determined. Use additional code(s) for all manifestations of poisonings.

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 Yes · 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.

Filter table of drugs and chemicals:

Substance	Accidental	Self-harm	Assault	Undetermined	Adverse Effect	Underdosing
Cerebral stimulants	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Cerebral stimulants::psychotherapeutic	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Cerebral stimulants::specified NEC	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Psychostimulant	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Psychostimulant::amphetamine	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Psychostimulant::caffeine	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Psychostimulant::methylphenidate	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Psychostimulant::specified NEC	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Stimulant	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Stimulant::central nervous system [See Also: Psychostimulant]	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Stimulant::central nervous system [See Also: Psychostimulant]::analeptics	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Stimulant::central nervous system [See Also: Psychostimulant]::opiate antagonist	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Stimulant::central nervous system [See Also: Psychostimulant]::psychotherapeutic NEC [See Also: Psychotherapeutic drug]	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Stimulant::central nervous system [See Also: Psychostimulant]::specified NEC	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606
Stimulant::respiratory	T43.601	T43.602	T43.603	T43.604	T43.605	T43.606

Patient EducationClinical

Poisoning

A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be poisonous if too much is taken. Poisons can include:

Read the full article at MedlinePlus

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

Convert T43.603S to ICD-9-CMHistory

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

ICD-9-CM

909.0 Late eff drug poisoning

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

E969 Late effect assault

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 T43.603SOverview

Is T43.603S (Poisoning by unspecified psychostimulants, assault) a billable code?

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

What does the 7th character S in T43.603S mean?

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

What MS-DRG does T43.603S group to?

When poisoning by unspecified psychostimulants, assault, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T43.603S 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 poisoning by unspecified psychostimulants, assault, sequela on inpatient claims.

What is the ICD-9 equivalent of T43.603S?

Under the General Equivalence Mappings, poisoning by unspecified psychostimulants, assault, sequela converts to ICD-9-CM 909.0 (late eff drug poisoning) and E969 (late effect assault). The mapping is approximate, so confirm the match fits the documentation.

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.

Indicator	Meaning	CMS pays CC/MCC DRG
Y	Diagnosis was present at the time of inpatient admission	Yes
N	Diagnosis was not present at the time of admission	No
U	Documentation is insufficient to determine	No
W	Clinically undetermined	Yes
1	Unreported, exempt from POA reporting	No