2026 ICD-10-CM Diagnosis Code T50.A94SPoisoning by other bacterial vaccines, undetermined, sequela

ICD-10-CM Codes›S00–T88›T36-T50›T50

ICD-10-CM T50.A94S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T50.A94S is a billable ICD-10-CM diagnosis code for poisoning by other bacterial vaccines, undetermined, 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 Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T50.A94S
Billable Status
Yes — Valid for Submission
Code Describes
Poisoning by other bacterial vaccines, undetermined, sequela
Short Description
Poisoning by other bacterial vaccines, undetermined, sequela
Same as the full description in the CMS dataset.
Parent Code
T50.A94
Poisoning by other bacterial vaccines, undetermined

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.A94SPoisoning by other bacterial vaccines, undetermined, sequela

Present on Admission (POA)Billing

T50.A94S 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 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 Yes · outpatient Yes

Clinical InformationClinical

  • Plague Vaccine

    a suspension of killed yersinia pestis used for immunizing people in enzootic plague areas.

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
BCG (vaccine)T50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Cholera vaccineT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Meningococcal vaccineT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Menningovax (-AC) (-C)T50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Paratyphoid vaccineT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Plague vaccineT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Rickettsial vaccine NECT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Rocky Mountain spotted fever vaccineT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Tetanus toxoid or vaccineT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Tetanus toxoid or vaccine::antitoxinT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Tetanus toxoid or vaccine::immune globulin (human)T50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Tetanus toxoid or vaccine::toxoidT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Tetanus toxoid or vaccine::toxoid::with diphtheria toxoidT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Tetanus toxoid or vaccine::toxoid::with diphtheria toxoid::with pertussisT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Typhoid-paratyphoid vaccineT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96
Typhus vaccineT50.A91T50.A92T50.A93T50.A94T50.A95T50.A96

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 T50.A94S 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
E989 Late eff inj-undet circ
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 T50.A94SOverview

Is T50.A94S (Poisoning by other bacterial vaccines, undetermined) a billable code?

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

What does the 7th character S in T50.A94S mean?

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

What MS-DRG does T50.A94S group to?

When poisoning by other bacterial vaccines, undetermined, 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 T50.A94S 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 other bacterial vaccines, undetermined, sequela on inpatient claims.

What is the ICD-9 equivalent of T50.A94S?

Under the General Equivalence Mappings, poisoning by other bacterial vaccines, undetermined, sequela converts to ICD-9-CM 909.0 (late eff drug poisoning) and E989 (late eff inj-undet circ). 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.