ICD-10-CM 2027 diagnosis code
T50.APoisoning by, adverse effect of and underdosing of bacterial vaccines
T50.A is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it and add the required 7th character.Short description: Bacterial vaccines
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About T50.A
T50.A is the ICD-10-CM diagnosis code for poisoning by, adverse effect of and underdosing of bacterial vaccines. It belongs to category T50 (poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances), block T36-T50 (poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.
Within T50 (poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances), T50.A is specifically for poisoning by, adverse effect of and underdosing of bacterial vaccines. Related codes cover mineralocorticoids and their antagonists (T50.0), loop [high-ceiling] diuretics (T50.1), carbonic-anhydrase inhibitors, benzothiadiazides and other diuretics (T50.2), electrolytic, caloric and water-balance agents (T50.3), drugs affecting uric acid metabolism (T50.4), appetite depressants (T50.5), antidotes and chelating agents (T50.6), analeptics and opioid receptor antagonists (T50.7) and 4 more.
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
7th character
The appropriate 7th character is to be added to each code from category T50
- T50.A1Poisoning by, adverse effect of and underdosing of pertussis vaccine, including combinations with a pertussis component
- T50.A11Poisoning by pertussis vaccine, including combinations with a pertussis component, accidental (unintentional)
- T50.A12Poisoning by pertussis vaccine, including combinations with a pertussis component, intentional self-harm
- T50.A13Poisoning by pertussis vaccine, including combinations with a pertussis component, assault
- T50.A14Poisoning by pertussis vaccine, including combinations with a pertussis component, undetermined
- T50.A15Adverse effect of pertussis vaccine, including combinations with a pertussis component
- T50.A16Underdosing of pertussis vaccine, including combinations with a pertussis component
- T50.A2Poisoning by, adverse effect of and underdosing of mixed bacterial vaccines without a pertussis component
- T50.A21Poisoning by mixed bacterial vaccines without a pertussis component, accidental (unintentional)
- T50.A22Poisoning by mixed bacterial vaccines without a pertussis component, intentional self-harm
- T50.A23Poisoning by mixed bacterial vaccines without a pertussis component, assault
- T50.A24Poisoning by mixed bacterial vaccines without a pertussis component, undetermined
- T50.A25Adverse effect of mixed bacterial vaccines without a pertussis component
- T50.A26Underdosing of mixed bacterial vaccines without a pertussis component
- T50.A9Poisoning by, adverse effect of and underdosing of other bacterial vaccines
- T50.A91Poisoning by other bacterial vaccines, accidental (unintentional)
- T50.A92Poisoning by other bacterial vaccines, intentional self-harm
- T50.A93Poisoning by other bacterial vaccines, assault
- T50.A94Poisoning by other bacterial vaccines, undetermined
- T50.A95Adverse effect of other bacterial vaccines
- T50.A96Underdosing of other bacterial vaccines
- Ainitial encounter
- Dsubsequent encounter
- Ssequela
Notes that apply from higher levels
Instructions written at a parent level also apply to T50.A.
Codes whose notes reference T50.A
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about T50.A
Is T50.A billable?
- No. T50.A is a header code. Report one of its more specific subcodes instead.