2027 ICD-10-CM Diagnosis Code T36.1X5SAdverse effect of cephalosporins and other beta-lactam antibiotics, sequela

ICD-10-CM Codes›S00–T88›T36-T50›T36

ICD-10-CM T36.1X5S
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T36.1X5S is a billable ICD-10-CM diagnosis code for adverse effect of cephalosporins and other beta-lactam antibiotics, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 922 through 923. The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T36.1X5S
Billable Status
Yes — Valid for Submission
Code Describes
Adverse effect of cephalosporins and other beta-lactam antibiotics, sequela
Short Description
Advrs effect of cephalospor/oth beta-lactm antibiot, sequela
Parent Code
Adverse effect of cephalosporins and other beta-lactam antibiotics

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT36-T50Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances
CategoryT36Poisoning by, adverse effect of and underdosing of systemic antibiotics
This CodeT36.1X5SAdverse effect of cephalosporins and other beta-lactam antibiotics, sequela

Code EditsBilling

Medicare Code Editor checks that affect claim validity for T36.1X5S.

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.

Present on Admission (POA)Billing

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adverse reaction to amoxicillin and/or clavulanic acid
  • Adverse reaction to clavulanic acid and/or ticarcillin
  • Adverse reaction to piperacillin and/or tazobactam
  • Aztreonam adverse reaction
  • Beta lactam adverse reaction
  • Carbapenem adverse reaction
  • Cefaclor adverse reaction
  • Cefadroxil adverse reaction
  • Cefixime adverse reaction
  • Cefodizime adverse reaction
  • Cefotaxime adverse reaction
  • Cefoxitin adverse reaction
  • Cefpirome adverse reaction
  • Cefpodoxime adverse reaction
  • Cefsulodin adverse reaction
  • Ceftazidime adverse reaction
  • Ceftibuten adverse reaction
  • Ceftizoxime adverse reaction
  • Ceftriaxone adverse reaction
  • Cefuroxime adverse reaction
  • Cephalexin adverse reaction
  • Cephalosporin adverse reaction
  • Cephalothin adverse reaction
  • Cephamandole adverse reaction
  • Cephamycin adverse reaction
  • Cephazolin adverse reaction
  • Cephradine adverse reaction
  • First generation cephalosporin adverse reaction
  • Fourth generation cephalosporin adverse reaction
  • Latamoxef adverse reaction
  • Monobactam adverse reaction
  • Second generation cephalosporin adverse reaction
  • Third generation cephalosporin adverse reaction

Coding GuidelinesGuidance

When coding an adverse effect of a drug that has been correctly prescribed and properly administered, assign the appropriate code for the nature of the adverse effect followed by the appropriate code for the adverse effect of the drug.

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 applicable episode of care:

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

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027, published by CMS and the National Center for Health Statistics.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to T36.1X5S: its own notes plus those printed at T36, block T36-T50, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • 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

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From T36 Poisoning by, adverse effect of and underdosing of systemic antibiotics applies to 198 codes
  • 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)
From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • toxic reaction to local anesthesia in pregnancy (O29.3-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • abuse and dependence of psychoactive substances (F10-F19)
  • abuse of non-dependence-producing substances (F55.-)
  • immunodeficiency due to drugs (D84.821)
  • drug reaction and poisoning affecting newborn (P00-P96)
  • pathological drug intoxication (inebriation) (F10-F19)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes

Code First

The underlying condition named in the note is sequenced before this code.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • for adverse effects, the nature of the adverse effect, such as:
  • adverse effect NOS (T88.7)
  • aspirin gastritis (K29.-)
  • blood disorders (D56-D76)
  • contact dermatitis (L23-L25)
  • dermatitis due to substances taken internally (L27.-)
  • nephropathy (N14.0-N14.2)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • code(s) to specify:
  • manifestations of poisoning
  • underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
  • underdosing of medication regimen (Z91.12-, Z91.13-)
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • code to identify any retained foreign body, if applicable (Z18.-)

Notes

General instructions on how these codes are used.

From Block T36-T50 Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances applies to 3,186 codes
  • The drug giving rise to the adverse effect should be identified by use of codes from categories T36-T50 with fifth or sixth character 5.
From Chapter 19 (S00-T88) Injury, poisoning and certain other consequences of external causes applies to 41,187 codes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

7th Character

Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.

From T36 Poisoning by, adverse effect of and underdosing of systemic antibiotics applies to 198 codes
  • The appropriate 7th character is to be added to each code from category T36
  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela this code

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ075
Poisoning/toxic effect/adverse effects/underdosing, sequela
Default principal diagnosis: inpatient No · outpatient Yes

Table of Drugs and ChemicalsClinical

Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.

SubstanceAccidentalSelf-harmAssaultUndeter­minedAdverse
Effect
Under­dosing
Antibiotic NEC::cephalosporin (group)T36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
Antibiotic NEC::b-lactam NECT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
AztreonamT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefacetrileT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefaclorT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefadroxilT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefalexinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefaloglycinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefaloridineT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefalosporinsT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefalotinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefamandoleT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
Cefamycin antibioticT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefapirinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefatrizineT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefazedoneT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefazolinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefbuperazoneT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefetametT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefiximeT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefmenoximeT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefmetazoleT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefminoxT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefonicidT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefoperazoneT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CeforanideT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefotaximeT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefotetanT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefotiamT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefoxitinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefpimizoleT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefpiramideT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefradineT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefroxadineT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefsulodinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CeftazidimeT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefteramT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CeftezoleT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CeftizoximeT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CeftriaxoneT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefuroximeT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CefuzonamT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CephalexinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CephaloglycinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CephaloridineT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CephalosporinsT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CephalothinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CephalotinT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
CephradineT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
Clavulanic acidT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
FlomoxefT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6
LatamoxefT36.1X1T36.1X2T36.1X3T36.1X4T36.1X5T36.1X6

Patient EducationClinical

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.

The full article covers:

  • What are antibiotics?
  • What do antibiotics treat?
  • Do antibiotics treat viral infections?
  • What are the side effects of antibiotics?
  • Why is it important to take antibiotics only when they're needed?
  • How do I use antibiotics correctly?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert T36.1X5S to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
909.5 Lte efct advrs efct drug
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
E930.5 Adv eff cephalosporin
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About T36.1X5SOverview

Is T36.1X5S a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report adverse effect of cephalosporins and other beta-lactam antibiotics, sequela on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character S in T36.1X5S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the adverse effect of cephalosporins and other beta-lactam antibiotics itself has resolved, not the original event.

What MS-DRG does T36.1X5S group to?

On inpatient claims, adverse effect of cephalosporins and other beta-lactam antibiotics, sequela maps to MS-DRG 923, 922, with relative weights from 0.9980 to 1.6248 depending on complications. Higher weights mean higher Medicare reimbursement.

Can T36.1X5S be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because adverse effect of cephalosporins and other beta-lactam antibiotics, sequela describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is T36.1X5S exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for adverse effect of cephalosporins and other beta-lactam antibiotics, sequela on inpatient claims. The code appears in the Poisoning by, adverse effect of and underdosing of drugs, medicaments and biological substances (T36-T50) range of the CMS exempt list.