ICD-10-CM 2027 diagnosis code
T46.995AAdverse effect of other agents primarily affecting the cardiovascular system, initial encounter
T46.995A is a valid, billable ICD-10-CM code for adverse effect of other agents primarily affecting the cardiovascular system, initial encounter. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Adverse effect of agents aff the cardiovascular sys, init
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 T46.995A
T46.995A is the ICD-10-CM diagnosis code for adverse effect of other agents primarily affecting the cardiovascular system, initial encounter. It belongs to category T46 (poisoning by, adverse effect of and underdosing of agents primarily affecting the cardiovascular system), 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 791 (Prematurity with Major Problems, relative weight 4.1075), DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), 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 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period) and 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 is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Before ICD-10, this condition was coded in ICD-9-CM as 995.29 (unspecified adverse effect of other drug, medicinal and biological substance) and E942.9 (other and unspecified agents primarily affecting the cardiovascular system causing adverse effects in therapeutic use).
7th character
Ainitial encounter
Other encounter types for T46.995:
Notes that apply from higher levels
Instructions written at a parent level also apply to T46.995A.
› From T46 Poisoning by, adverse effect of and underdosing of agents primarily affecting the cardiovascular system
- poisoning by, adverse effect of and underdosing of metaraminol (T44.4)
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 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period
MDC 15 · Newborns and Other Neonates with Conditions Originating in the Perinatal Period
MDC 21 · Injuries, Poisonings and Toxic Effects of Drugs
ICD-9-CM equivalent
Converter →- 995.29Unspecified adverse effect of other drug, medicinal and biological substanceapproximate, combination
- E942.9Other and unspecified agents primarily affecting the cardiovascular system causing adverse effects in therapeutic useapproximate, combination
From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.
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 T46.995A
Is T46.995A billable?
- Yes. T46.995A 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 T46.995A 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 T46.995A be used as a principal diagnosis?
- No. It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.
Is T46.995A a CC or MCC?
- No. T46.995A is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does T46.995A group to?
- T46.995A is used in the MS-DRG v44.0 logic for MS-DRG 791 (Prematurity with Major Problems), MS-DRG 793 (Full Term Neonate with Major Problems), 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.
What is the ICD-9 code for T46.995A?
- The CMS General Equivalence Mappings map T46.995A to ICD-9-CM 995.29 and E942.9.