T36.0X5A — Adverse effect of penicillins, initial encounter

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0 (FY2026), Appendix B.

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.

Adverse effect of penicillins, initial encounter is a billable ICD-10-CM diagnosis code (T36.0X5A).

Sequencing, inclusion, and exclusion notes published for T36.0X5A in the official ICD-10-CM tabular list.

Conditions the official ICD-10-CM tabular list includes under this code.

adverse effect of correct substance properly administered
poisoning by overdose of substance
poisoning by wrong substance given or taken in error
underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed

Conditions that can never be reported with this code; the two are mutually exclusive.

antineoplastic antibiotics (T45.1-)
locally applied antibiotic NEC (T49.0)
topically used antibiotic for ear, nose and throat (T49.6)
topically used antibiotic for eye (T49.5)
toxic reaction to local anesthesia in pregnancy (O29.3-)

Conditions not covered by this code, but which may be reported alongside it when both are present.

abuse and dependence of psychoactive substances (F10-F19)
abuse of non-dependence-producing substances (F55.-)
immunodeficiency due to drugs (D84.821)
drug reaction and poisoning affecting newborn (P00-P96)
pathological drug intoxication (inebriation) (F10-F19)

Underlying conditions that must be sequenced before this code.

Supplementary codes the tabular list directs you to add.

Use additional code(s) to specify:
manifestations of poisoning
underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
underdosing of medication regimen (Z91.12-, Z91.13-)

Yes. The appropriate 7th character is to be added to each code from category T36.

Official ICD-10-CM classifications closest to T36.0X5A in its code family, with their registry titles.

Substances from the official ICD-10-CM Table of Drugs and Chemicals that map to this code.