2026 ICD-10-CM Diagnosis Code T50.B12SPoisoning by smallpox vaccines, intentional self-harm, sequela
T50.B12S is a billable ICD-10-CM diagnosis code for poisoning by smallpox vaccines, intentional self-harm, 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
Code Classification
Present on Admission (POA)Billing
T50.B12S 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.
Clinical InformationClinical
Smallpox Vaccine
a vaccinia virus vaccine used for immunization against smallpox. it is now recommended only for laboratory workers exposed to smallpox virus. certain countries continue to vaccinate those in the military service. rare complications most often associated with older generation smallpox vaccines include vaccinia, secondary bacterial infections, and encephalomyelitis. because monkeypox virus and smallpox virus are both orthopoxvirus and are closely related smallpox vaccines provide effective cross-protection against mpox, monkeypox (https://www.cdc.gov/poxvirus/monkeypox/clinicians/smallpox-vaccine.html).
Table of Drugs and ChemicalsClinical
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.B12S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T50.B12SOverview
Is T50.B12S (Poisoning by smallpox vaccines, intentional self-harm) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by smallpox vaccines, intentional self-harm, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T50.B12S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by smallpox vaccines, intentional self-harm itself has resolved, not the original event.
What MS-DRG does T50.B12S group to?
When poisoning by smallpox vaccines, intentional self-harm, 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.B12S 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 smallpox vaccines, intentional self-harm, sequela on inpatient claims.
What is the ICD-9 equivalent of T50.B12S?
Under the General Equivalence Mappings, poisoning by smallpox vaccines, intentional self-harm, sequela converts to ICD-9-CM 909.0 (late eff drug poisoning) and E959 (late eff of self-injury). 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.
