ICD-10-CM 2027 diagnosis code
T43.643APoisoning by ecstasy, assault, initial encounter
T43.643A is a valid, billable ICD-10-CM code for poisoning by ecstasy, assault, initial encounter. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.
Code last changed in FY2019 (effective October 1, 2018). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About T43.643A
T43.643A is the ICD-10-CM diagnosis code for poisoning by ecstasy, assault, initial encounter. It belongs to category T43 (poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified), 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 billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
The 7th character "A" means initial encounter: use it while the patient is receiving active treatment for the condition.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 917 (Poisoning and Toxic Effects of Drugs with MCC, relative weight 1.57) and DRG 918 (Poisoning and Toxic Effects of Drugs without MCC, relative weight 0.872), in MDC 21 (Injuries, Poisonings and Toxic Effects of Drugs), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It was added in FY2019, effective October 1, 2018.
7th character
Ainitial encounter
Other encounter types for T43.643:
Notes that apply from higher levels
Instructions written at a parent level also apply to T43.643A.
› From T43.6 Poisoning by, adverse effect of and underdosing of psychostimulants
- poisoning by, adverse effect of and underdosing of cocaine (T40.5-)
› From T43 Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified
Broader instructions also apply from 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.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 21 · Injuries, Poisonings and Toxic Effects of Drugs
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2019 (effective 10/1/2018): Added
- No changes since FY2019.
Common questions about T43.643A
Is T43.643A billable?
- Yes. T43.643A is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
What does the "A" at the end of T43.643A mean?
- It is the 7th character for initial encounter. Per the official guidelines, use it while the patient is receiving active treatment for the condition.
Can T43.643A be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict T43.643A as a principal diagnosis.
Is T43.643A a CC or MCC?
- No. T43.643A is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does T43.643A group to?
- T43.643A is used in the MS-DRG v44.0 logic for MS-DRG 917 (Poisoning and Toxic Effects of Drugs with MCC) and MS-DRG 918 (Poisoning and Toxic Effects of Drugs without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.