2022 ICD-10-CM Code T45.0X6A

Underdosing of antiallergic and antiemetic drugs, initial encounter

Version 2021

Valid for Submission

ICD-10:T45.0X6A
Short Description:Underdosing of antiallergic and antiemetic drugs, init
Long Description:Underdosing of antiallergic and antiemetic drugs, initial encounter

Code Classification

  • Injury, poisoning and certain other consequences of external causes (S00–T98)
    • Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances (T36-T50)
      • Primarily systemic and hematological agents, NEC (T45)

T45.0X6A is a billable diagnosis code used to specify a medical diagnosis of underdosing of antiallergic and antiemetic drugs, initial encounter. The code T45.0X6A is valid during the fiscal year 2022 from October 01, 2021 through September 30, 2022 for the submission of HIPAA-covered transactions.

The code T45.0X6A describes a circumstance which influences the patient's health status but not a current illness or injury. The code is unacceptable as a principal diagnosis.

T45.0X6A is an initial encounter code, includes a 7th character and should be used while the patient is receiving active treatment for a condition like underdosing of antiallergic and antiemetic drugs. According to ICD-10-CM Guidelines an "initial encounter" doesn't necessarily means "initial visit". The 7th character should be used when the patient is undergoing active treatment regardless if new or different providers saw the patient over the course of a treatment. The appropriate 7th character codes should also be used even if the patient delayed seeking treatment for a condition.

Coding Guidelines

Underdosing refers to taking less of a medication than is prescribed by a provider or a manufacturer's instruction. Codes for underdosing should never be assigned as principal or first-listed codes. If a patient has a relapse or exacerbation of the medical condition for which the drug is prescribed because of the reduction in dose, then the medical condition itself should be coded.

The appropriate 7th character is to be added to each code from block Primarily systemic and hematological agents, NEC (T45). Use the following options for the aplicable episode of care:

Code Edits

The Medicare Code Editor (MCE) detects and reports errors in the coding of claims data. The following ICD-10 Code Edits are applicable to this code:

Convert T45.0X6A to ICD-9 Code

Information for Patients


Medication Errors

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Food and Drug Administration


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Code History

  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016 (First year ICD-10-CM implemented into the HIPAA code set)