ICD-10-CM Diagnosis Code T36.8X6S - Underdosing of other systemic antibiotics, sequela (original) (raw)
ICD List 2025-2026 Edition
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- 2026 ICD-10-CM Code T36.8X6S
Underdosing of other systemic antibiotics, sequela
ICD-10-CM Code:
T36.8X6S
ICD-10 Code for:
Underdosing of other systemic antibiotics, sequela
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:
T36.8X6S is a billable diagnosis code used to specify a medical diagnosis of underdosing of other systemic antibiotics, sequela. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026. The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.
This code 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.
T36.8X6S is a sequela code, includes a 7th character and should be used for complications that arise as a direct result of a condition like underdosing of other systemic antibiotics. According to ICD-10-CM Guidelines a "sequela" code should be used for chronic or residual conditions that are complications of an initial acute disease, illness or injury. The most common sequela is pain. Usually, two diagnosis codes are needed when reporting sequela. The first code describes the nature of the sequela while the second code describes the sequela or late effect.
- Code Information
- Clinical Classification
- Clinical Information
- Coding Guidelines
- Replaced Code
- Tabular List of Diseases and Injuries
- Code Edits
- Diagnostic Related Groups Mapping
- Present on Admission (POA)
- Convert to ICD-9 Code
- Table of Drugs and Chemicals
- Patient Education
- Other Codes Used Similar Conditions
- Code History
- Injury, poisoning and certain other consequences of external causes
S00–T88
Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.
They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.
CCSR Code: INJ075
Inpatient Default: X - Not applicable.
Outpatient Default: X - Not applicable.
Capreomycin
cyclic peptide antibiotic similar to viomycin. it is produced by streptomyces capreolus.
Ciprofloxacin
a broad-spectrum antimicrobial carboxyfluoroquinoline.
Clindamycin
an antibacterial agent that is a semisynthetic analog of lincomycin.
Colistin
cyclic polypeptide antibiotic from bacillus colistinus. it is composed of polymyxins e1 and e2 (or colistins a, b, and c) which act as detergents on cell membranes. colistin is less toxic than polymyxin b, but otherwise similar; the methanesulfonate is used orally.
Enoxacin
a broad-spectrum 6-fluoronaphthyridinone antibacterial agent that is structurally related to nalidixic acid.
Enviomycin
cyclic basic peptide related to viomycin. it is isolated from an induced mutant of streptomyces griseoverticillatus var. tuberacticus and acts as an antitubercular agent with less ototoxicity than tuberactinomycin.
Fleroxacin
a broad-spectrum antimicrobial fluoroquinolone. the drug strongly inhibits the dna-supercoiling activity of dna gyrase.
Fosfomycin
an antibiotic produced by streptomyces fradiae.
Fusidic Acid
an antibiotic isolated from the fermentation broth of fusidium coccineum. (from merck index, 11th ed). it acts by inhibiting translocation during protein synthesis.
Lincomycin
an antibiotic produced by streptomyces lincolnensis var. lincolnensis. it has been used in the treatment of staphylococcal, streptococcal, and bacteroides fragilis infections.
Norfloxacin
a synthetic fluoroquinolone (fluoroquinolones) with broad-spectrum antibacterial activity against most gram-negative and gram-positive bacteria. norfloxacin inhibits bacterial dna gyrase.
Levofloxacin
the l-isomer of ofloxacin.
Ofloxacin
a synthetic fluoroquinolone antibacterial agent that inhibits the supercoiling activity of bacterial dna gyrase, halting dna replication.
Ristocetin
an antibiotic mixture of two components, a and b, obtained from nocardia lurida (or the same substance produced by any other means). it is no longer used clinically because of its toxicity. it causes platelet agglutination and blood coagulation and is used to assay those functions in vitro.
von Willebrand Factor
a high-molecular-weight plasma protein, produced by endothelial cells and megakaryocytes, that is part of the factor viii/von willebrand factor complex. the von willebrand factor has receptors for collagen, platelets, and ristocetin activity as well as the immunologically distinct antigenic determinants. it functions in adhesion of platelets to collagen and hemostatic plug formation. the prolonged bleeding time in von willebrand diseases is due to the deficiency of this factor.
Teicoplanin
lipoglycopeptide antibiotic from actinoplanes teichomyceticus active against gram-positive bacteria. it consists of five major components each with a different fatty acid moiety.
Vancomycin
antibacterial obtained from streptomyces orientalis. it is a glycopeptide related to ristocetin that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear.
Vancomycin Resistance
nonsusceptibility of bacteria to the action of vancomycin, an inhibitor of cell wall synthesis.
Vancomycin-Resistant Enterococci
strains of the genus enterococcus that are resistant to the antibiotic vancomycin. the enterococci become resistant by acquiring plasmids carrying genes for vancomycin resistance.
Vancomycin-Resistant Staphylococcus aureus
isolates of the staphylococcus aureus that are resistant to the antibiotic vancomycin. the s. aureus becomes resistant by acquiring plasmids carrying genes for vancomycin resistance. vancomycin‐intermediate s. aureus has low-level vancomycin resistance requiring an intermediate concentration of vancomycin between sensitive and resistant isolates. these s. aureus with reduced susceptibility to vancomycin and related glycopeptide antibiotics are often seen in healthcare associated infections.
Viomycin
a strongly basic peptide, antibiotic complex from several strains of streptomyces. it is allergenic and toxic to kidneys and the labyrinth. viomycin is used in tuberculosis as several different salts and in combination with other agents.
Streptogramin A
a specific streptogramin group a antibiotic produced by streptomyces graminofaciens and other bacteria.
Virginiamycin
a cyclic polypeptide antibiotic complex from streptomyces virginiae, s. loidensis, s. mitakaensis, s. pristina-spiralis, s. ostreogriseus, and others. it consists of 2 major components, virginiamycin factor m1 and virginiamycin factor s1. it is used to treat infections with gram-positive organisms and as a growth promoter in cattle, swine, and poultry.
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 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
This code was replaced in the 2026 ICD-10-CM code set with the code(s) listed below. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2025. This code was replaced for the FY 2026 (October 1, 2025 - September 30, 2026).
- T36.AX6S - Underdosing of fluoroquinolone antibiotics, sequela
- T36.AX6S - Underdosing of fluoroquinolone antibiotics, sequela
The Medicare Code Editor (MCE) detects errors and inconsistencies in ICD-10-CM diagnosis coding that can affect Medicare claim validity. These Medicare code edits help medical coders and billing professionals determine when a diagnosis code is not appropriate as a principal diagnosis, does not meet coverage criteria. Use this list to verify whether a code is valid for Medicare billing and to avoid claim rejections or denials due to diagnosis coding issues.
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.
T36.8X6S is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here.
CMS POA Indicator Options and Definitions
POA Indicator: Y
Reason: Diagnosis was present at time of inpatient admission.
CMS Pays CC/MCC DRG? YES
POA Indicator: N
Reason: Diagnosis was not present at time of inpatient admission.
CMS Pays CC/MCC DRG? NO
POA Indicator: U
Reason: Documentation insufficient to determine if the condition was present at the time of inpatient admission.
CMS Pays CC/MCC DRG? NO
POA Indicator: W
Reason: Clinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.
CMS Pays CC/MCC DRG? YES
POA Indicator: 1
Reason: Unreported/Not used - Exempt from POA reporting.
CMS Pays CC/MCC DRG? NO
Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.
Approximate Flag - The approximate mapping means this ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option, but it may not fully capture the original diagnosis or clinical intent.
The parent code T36.8X6 of the current diagnosis code is referenced in the Table of Drugs and Chemicals, this table contains a classification of drugs, industrial solvents, corrosive gases, noxious plants, pesticides, and other toxic agents.
According to ICD-10-CM coding guidelines it is advised to do not code directly from the Table of Drugs and Chemicals, instead always refer back to the Tabular List when doing the initial coding. Each substance in the table is assigned a code according to the poisoning classification and external causes of adverse effects. It is important to use as many codes as necessary to specify all reported drugs, medicinal or chemical substances. If the same diagnosis code describes the causative agent for more than one adverse reaction, poisoning, toxic effect or underdosing, utilize the code only once.
Filter table of drugs and chemicals:
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
FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
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.