2027 ICD-10-CM Diagnosis Code T43.211SPoisoning by selective serotonin and norepinephrine reuptake inhibitors, accidental (unintentional), sequela

ICD-10-CM Codes›S00–T88›T36-T50›T43

ICD-10-CM T43.211S
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T43.211S is a billable ICD-10-CM diagnosis code for poisoning by selective serotonin and norepinephrine reuptake inhibitors, accidental (unintentional), 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 exempt from POA reporting. Coders also document this condition as accidental trazodone overdose. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T43.211S
Billable Status
Yes — Valid for Submission
Code Describes
Poisoning by selective serotonin and norepinephrine reuptake inhibitors, accidental (unintentional), sequela
Short Description
Poisn by slctv seroton/norepineph reup inhibtr, acc, sqla
Parent Code
Poisoning by selective serotonin and norepinephrine reuptake inhibitors, accidental (unintentional)

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
CategoryT43Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified
This CodeT43.211SPoisoning by selective serotonin and norepinephrine reuptake inhibitors, accidental (unintentional), sequela

Present on Admission (POA)Billing

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Accidental trazodone overdose
  • Accidental trazodone poisoning
  • Accidental venlafaxine overdose
  • Accidental venlafaxine poisoning
  • Norepinephrine reuptake inhibitor and serotonin reuptake inhibitor overdose
  • Norepinephrine reuptake inhibitor overdose
  • Trazodone overdose
  • Trazodone poisoning
  • Venlafaxine overdose
  • Venlafaxine poisoning

Coding GuidelinesGuidance

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 psychotropic drugs, not elsewhere classified (T43). 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 T43.211S: its own notes plus those printed at T43, 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 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 T43 Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified applies to 354 codes
  • appetite depressants (T50.5-)
  • barbiturates (T42.3-)
  • benzodiazepines (T42.4-)
  • drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.- -F19.-)
  • methaqualone (T42.6-)
  • psychodysleptics [hallucinogens] (T40.7-T40.9-)
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 T43 Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified applies to 354 codes
  • The appropriate 7th character is to be added to each code from category T43
  • Ainitial encounter
  • Dsubsequent encounter
  • Ssequela this code

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name T43.211S, its category, or a range that includes it.

Code First 1

These codes say to code first a condition named in the note, and T43.211S is one of the conditions named.

  • G90.81 Serotonin syndrome
    selective serotonin and norepinephrine reuptake inhibitors [SSNRI] (T43.21 with sixth character 1-4) names T43.21, which includes this code

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 Yes · outpatient Yes

Clinical InformationClinical

  • Trazodone

    a serotonin uptake inhibitor that is used as an antidepressive agent. it has been shown to be effective in patients with major depressive disorders and other subsets of depressive disorders. it is generally more useful in depressive disorders associated with insomnia and anxiety. this drug does not aggravate psychotic symptoms in patients with schizophrenia or schizoaffective disorders. (from ama drug evaluations annual, 1994, p309)

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
Antidepressant::selective serotonin norepinephrine reuptake inhibitorT43.211T43.212T43.213T43.214T43.215T43.216
Antidepressant::triazolopyridineT43.211T43.212T43.213T43.214T43.215T43.216
TrazodoneT43.211T43.212T43.213T43.214T43.215T43.216
VenlafaxineT43.211T43.212T43.213T43.214T43.215T43.216

Patient EducationClinical

Antidepressants

Antidepressants are prescription medicines to treat depression. Depression is more than feeling a little sad or "blue" for a few days. It's a very common, serious medical illness that affects your mood and general mental health. It can make you feel tired, hopeless, worried, or fearful. It can change your thinking, sleeping, and eating.

The full article covers:

  • What are antidepressants?
  • Are antidepressants used for other conditions?
  • What are the different types of antidepressants?
  • Which type of antidepressant is right for me?
  • How long do antidepressants take to work?
  • How long will I need to take an antidepressant?
  • What are the side effects of antidepressants?
  • What can I do to take antidepressants safely?

Read the full article at MedlinePlus

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

Convert T43.211S to ICD-9-CMHistory

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

ICD-9-CM
909.0 Late eff drug poisoning
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
E929.2 Late eff acc poisoning
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 T43.211SOverview

Is T43.211S a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by selective serotonin and norepinephrine reuptake inhibitors, accidental (unintentional), sequela on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character S in T43.211S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by selective serotonin and norepinephrine reuptake inhibitors, accidental (unintentional) itself has resolved, not the original event.

What MS-DRG does T43.211S group to?

When poisoning by selective serotonin and norepinephrine reuptake inhibitors, accidental (unintentional), sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 923, 922, with relative weights from 0.9980 to 1.6248 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T43.211S 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 poisoning by selective serotonin and norepinephrine reuptake inhibitors, accidental (unintentional), 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.

Can T43.211S be reported with a code from O29.3?

Not as a rule. The Excludes1 note at block T36-T50, which applies to T43.211S, lists "toxic reaction to local anesthesia in pregnancy (O29.3-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).