August 26, 2025

Medical Coding From the ICD-10-CM Table of Drugs And Chemicals

AAPC | Certification | Certified Medical Coder | CPC | Medical Coding
By Janine Mothershed

What Is the Table of Drugs & Chemicals?

The Table of Drugs & Chemicals is an alphabetical list of substances—including prescription medications, over-the-counter drugs, alcohols, gases, industrial chemicals, and other agents—that can cause toxic or adverse effects.

For each substance, the table provides a set of possible categories and codes based on the circumstances of exposure or use.

ICD10Data Tab;e of Drugs https://www.icd10data.com/ICD10CM/Table_Of_Drugs

Steps to Use the Table

Identify the Substance

  • Review the provider documentation to determine the exact drug, chemical, or substance involved.

  • If the documentation is vague (e.g., “pain medication”), query the provider for clarification, since specificity is required.

Go to the Table of Drugs & Chemicals in the Alphabetic Index

  • Locate the substance in alphabetical order.

  • For example: Acetaminophen, Ibuprofen, Carbon Monoxide, or Bleach.

Choose the Correct Column

Each substance has rows with six columns that correspond to the nature of the encounter:

  1. Poisoning, Accidental (Unintentional) – Incorrect substance taken or wrong dose by mistake.

  2. Poisoning, Intentional Self-Harm – Substance taken deliberately with the intent to harm oneself.

  3. Poisoning, Assault – Substance administered by another person with the intent to harm.

  4. Poisoning, Undetermined – When it’s unclear whether the poisoning was accidental, intentional, or assault.

  5. Adverse Effect – A reaction to a substance taken correctly (e.g., prescribed dosage, but resulted in a side effect.

  6. Underdosing – When a patient takes less of a medication than prescribed,it often leads to worsening of the condition.

Verify the Code in the Tabular List

  • Always confirm the code in the Tabular List to ensure it matches documentation, includes the correct 7th character (if needed), and reflects any additional instructional notes.

  • The Table provides suggested categories, but the final code selection comes from the Tabular List.

Assign Additional Codes

  • If coding for poisoning, you may need to add codes for manifestations (e.g., seizures, coma).

  • For adverse effects, assign the code for the manifestation first, followed by the drug adverse effect code.

  • For underdosing, add a code to explain noncompliance or the reason for underdosing (e.g., financial hardship, patient refusal).

Example Scenarios

  • Case 1: Accidental overdose of Ibuprofen

    • Locate “Ibuprofen” in the Table → Poisoning, Accidental column → category T39.311A (Poisoning by ibuprofen, accidental, initial encounter).

    • Verify in Tabular List.

  • Case 2: Allergic reaction after correct penicillin use

    • Locate “Penicillin” → Adverse Effect column → category T36.0X5A.

    • Code the allergic reaction (e.g., urticaria) first, then add the adverse effect code.

  • Case 3: Patient intentionally takes too much acetaminophen

    • Locate “Acetaminophen” → Poisoning, Intentional Self-Harm column → T39.1X2A.

    • Confirm in Tabular List.

Key Tips for Coders

  • Do not assign codes directly from the Table—always verify in the Tabular List.

  • Pay attention to 7th characters: “A” (initial), “D” (subsequent), or “S” (sequela).

  • Be precise—look up the specific drug/chemical, not just the drug class, when possible.

  • Use additional external cause codes (e.g., place of occurrence, activity) if required by guidelines.

The Table of Drugs & Chemicals is your starting point for coding toxic effects, poisonings, adverse effects, and underdosing. Proper navigation—substance, column, verification in the Tabular List, and sequencing—ensures accurate ICD-10-CM reporting and supports quality healthcare data.

ICD-10 Steps https://codingclarified.com/medical-coding-steps-for-icd-10-cm/

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