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  6. 2025 ICD-10-CM Code T36

2025 ICD-10-CM Diagnosis Code T36

Poisoning by, adverse effect of and underdosing of systemic antibiotics

ICD-10-CM Code:
T36
ICD-10 Code for:
Systemic antibiotics
Is Billable?
Not Valid for Submission
Code Navigator:

T36 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of poisoning by, adverse effect of and underdosing of systemic antibiotics. The code is not specific and is NOT valid for the year 2025 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Systemic antibiotics

Non-specific codes like T36 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for systemic antibiotics:

  • T36.0 for Poisoning by, adverse effect of and underdosing of penicillins - NON-BILLABLE CODE

  • T36.0X for Poisoning by, adverse effect of and underdosing of penicillins - NON-BILLABLE CODE

  • T36.1 for Poisoning by, adverse effect of and underdosing of cephalosporins and other beta-lactam antibiotics - NON-BILLABLE CODE

  • T36.1X for Poisoning by, adverse effect of and underdosing of cephalosporins and other beta-lactam antibiotics - NON-BILLABLE CODE

  • T36.2 for Poisoning by, adverse effect of and underdosing of chloramphenicol group - NON-BILLABLE CODE

  • T36.2X for Poisoning by, adverse effect of and underdosing of chloramphenicol group - NON-BILLABLE CODE

  • T36.3 for Poisoning by, adverse effect of and underdosing of macrolides - NON-BILLABLE CODE

  • T36.3X for Poisoning by, adverse effect of and underdosing of macrolides - NON-BILLABLE CODE

  • T36.4 for Poisoning by, adverse effect of and underdosing of tetracyclines - NON-BILLABLE CODE

  • T36.4X for Poisoning by, adverse effect of and underdosing of tetracyclines - NON-BILLABLE CODE

  • T36.5 for Poisoning by, adverse effect of and underdosing of aminoglycosides - NON-BILLABLE CODE

  • T36.5X for Poisoning by, adverse effect of and underdosing of aminoglycosides - NON-BILLABLE CODE

  • T36.6 for Poisoning by, adverse effect of and underdosing of rifampicins - NON-BILLABLE CODE

  • T36.6X for Poisoning by, adverse effect of and underdosing of rifampicins - NON-BILLABLE CODE

  • T36.7 for Poisoning by, adverse effect of and underdosing of antifungal antibiotics, systemically used - NON-BILLABLE CODE

  • T36.7X for Poisoning by, adverse effect of and underdosing of antifungal antibiotics, systemically used - NON-BILLABLE CODE

  • T36.8 for Poisoning by, adverse effect of and underdosing of other systemic antibiotics - NON-BILLABLE CODE

  • T36.8X for Poisoning by, adverse effect of and underdosing of other systemic antibiotics - NON-BILLABLE CODE

  • T36.9 for Poisoning by, adverse effect of and underdosing of unspecified systemic antibiotic - NON-BILLABLE CODE

  • T36.91 for Poisoning by unspecified systemic antibiotic, accidental (unintentional) - NON-BILLABLE CODE

  • T36.92 for Poisoning by unspecified systemic antibiotic, intentional self-harm - NON-BILLABLE CODE

  • T36.93 for Poisoning by unspecified systemic antibiotic, assault - NON-BILLABLE CODE

  • T36.94 for Poisoning by unspecified systemic antibiotic, undetermined - NON-BILLABLE CODE

  • T36.95 for Adverse effect of unspecified systemic antibiotic - NON-BILLABLE CODE

  • T36.96 for Underdosing of unspecified systemic antibiotic - NON-BILLABLE CODE

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    S00–T88
    • Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
      T36-T50
      • Poisoning by, adverse effect of and underdosing of systemic antibiotics
        T36

Coding Guidelines

When coding a poisoning or reaction to the improper use of a medication (e.g., overdose, wrong substance given or taken in error, wrong route of administration), first assign the appropriate code from categories T36-T50. The poisoning codes have an associated intent as their 5th or 6th character (accidental, intentional self-harm, assault and undetermined. If the intent of the poisoning is unknown or unspecified, code the intent as accidental intent. The undetermined intent is only for use if the documentation in the record specifies that the intent cannot be determined. Use additional code(s) for all manifestations of poisonings.

The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of systemic antibiotics (T36). Use the following options for the aplicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Type 1 Excludes

Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • 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

7th Character Note

7th Character Note
Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.
  • The appropriate 7th character is to be added to each code from category T36

7th Character

7th Character
Indicates that a seventh character is to be assigned to codes in a subcategory.
  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Patient Education


Antibiotics

What are antibiotics?

Antibiotics are medicines that fight bacterial infections in people and animals. They work by killing the bacteria or by making it hard for the bacteria to grow and multiply.

Antibiotics can be taken in different ways:

  • Orally (by mouth). This could be pills, capsules, or liquids.
  • Topically. This might be a cream, spray, or ointment that you put on your skin. It could also be eye ointment, eye drops, or ear drops.
  • Through an injection or intravenously (IV). This is usually for more serious infections.

What do antibiotics treat?

Antibiotics only treat certain bacterial infections, such as strep throat, urinary tract infections, and E. coli.

You may not need to take antibiotics for some bacterial infections. For example, you might not need them for many sinus infections or some ear infections. Taking antibiotics when they're not needed won't help you, and they can have side effects. Your health care provider can decide the best treatment for you when you're sick. Don't ask your provider to prescribe an antibiotic for you.

Do antibiotics treat viral infections?

Antibiotics do not work on viral infections. For example, you shouldn't take antibiotics for:

  • Colds and runny noses, even if the mucus is thick, yellow, or green
  • Most sore throats (except strep throat)
  • Flu
  • Most cases of bronchitis

What are the side effects of antibiotics?

The side effects of antibiotics range from minor to very severe. Some of the common side effects include:

  • Rash
  • Nausea
  • Diarrhea
  • Yeast infections

More serious side effects can include:

  • C. diff infections, which cause diarrhea that can lead to severe colon damage and sometimes even death
  • Severe and life-threatening allergic reactions
  • Antibiotic resistance infections

Call your health care provider if you develop any side effects while taking your antibiotic.

Why is it important to take antibiotics only when they're needed?

You should only take antibiotics when they are needed because they can cause side effects and can contribute to antibiotic resistance. Antibiotic resistance happens when the bacteria change and become able to resist the effects of an antibiotic. This means that the bacteria continue to grow.

How do I use antibiotics correctly?

When you take antibiotics, it is important that you take them responsibly:

  • Always follow the directions carefully. Finish your medicine even if you feel better. If you stop taking them too soon, some bacteria may survive and re-infect you.
  • Don't save your antibiotics for later.
  • Don't share your antibiotic with others.
  • Don't take antibiotics prescribed for someone else. This may delay the best treatment for you, make you even sicker, or cause side effects.

Centers for Disease Control and Prevention


[Learn More in MedlinePlus]

Drug Reactions

Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions, such as drug interactions, side effects, and allergies.

What is a drug interaction?

A drug interaction is a change in the way a drug acts in the body when taken with certain other drugs, foods, or supplements or when taken while you have certain medical conditions. Examples include:

  • Two drugs, such as aspirin and blood thinners
  • Drugs and food, such as statins and grapefruit
  • Drugs and supplements, such as gingko and blood thinners
  • Drugs and medical conditions, such as aspirin and peptic ulcers

Interactions could cause a drug to be more or less effective, cause side effects, or change the way one or both drugs work.

What are side effects?

Side effects are unwanted, usually unpleasant, effects caused by medicines. Most are mild, such as a stomachache, dry mouth, or drowsiness, and go away after you stop taking the medicine. Others can be more serious. Sometimes a drug can interact with a disease that you have and cause a side effect. For example, if you have a heart condition, certain decongestants can cause you to have a rapid heartbeat.

What are drug allergies?

Drug allergies are another type of reaction. They can range from mild to life-threatening. Skin reactions, such as hives and rashes, are the most common type. Anaphylaxis, a serious allergic reaction, is less common.

How can I stay safe when taking medicines?

When you start a new prescription or over-the-counter medicine, make sure you understand how to take it correctly. Know which other medicines, foods, and supplements you need to avoid. Always talk to your health care provider or pharmacist if you have questions about your medicines.


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • 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. This was the first year ICD-10-CM was implemented into the HIPAA code set.