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T36.1X4 vs T36.1X5

T36.1X4 (Poisoning by cephalosporins and other beta-lactam antibiotics, undetermined) compared with T36.1X5 (Adverse effect of cephalosporins and other beta-lactam antibiotics), from the official CMS tabular data. T36.1X4 and T36.1X5 code the same substance (Aztreonam) with a different intent.

Can these codes be reported together?

Same substance, different intent. T36.1X4 and T36.1X5 code the same substance (Aztreonam) with a different circumstance of exposure.

From the CMS Table of Drugs and Chemicals: accidental poisoning, intentional self-harm, assault, undetermined intent, adverse effect and underdosing are mutually exclusive columns — only one of them applies to a given encounter.

Side by side

T36.1X4Poisoning by cephalosporins and other beta-lactam antibiotics, undeterminedT36.1X5Adverse effect of cephalosporins and other beta-lactam antibiotics
Billing statusNon-billable headerNon-billable header
ClassificationS00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)
DefinitionPoisoning by cephalosporins and other beta-lactam antibiotics, undetermined is a non-billable ICD-10-CM category code (T36.1X4).Adverse effect of cephalosporins and other beta-lactam antibiotics is a non-billable ICD-10-CM category code (T36.1X5).
7th characterThe appropriate 7th character is to be added to each code from category T36The appropriate 7th character is to be added to each code from category T36
Includes
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
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
Use additional code
code(s) to specify:
manifestations of poisoning
underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
code(s) to specify:
manifestations of poisoning
underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
Code first
, for adverse effects, the nature of the adverse effect, such as:
adverse effect NOS (T88.7)
, for adverse effects, the nature of the adverse effect, such as:
adverse effect NOS (T88.7)

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources