2026 ICD-10-CM Diagnosis Code T43.222APoisoning by selective serotonin reuptake inhibitors, intentional self-harm, initial encounter

ICD-10-CM Codes›S00–T88›T36-T50›T43

ICD-10-CM T43.222A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T43.222A is a billable ICD-10-CM diagnosis code for poisoning by selective serotonin reuptake inhibitors, intentional self-harm, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 917 through 918. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, self-harm; External cause codes: poisoning by drug; and Poisoning by drugs, initial encounter.

Code Identity

ICD-10-CM Code
T43.222A
Billable Status
Yes — Valid for Submission
Code Describes
Poisoning by selective serotonin reuptake inhibitors, intentional self-harm, initial encounter
Short Description
Poisn by slctv serotonin reuptake inhibtr, self-harm, init
Parent Code
T43.222
Poisoning by selective serotonin reuptake inhibitors, intentional self-harm

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 CodeT43.222APoisoning by selective serotonin reuptake inhibitors, intentional self-harm, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Citalopram overdose
  • Citalopram poisoning
  • Fluoxetine overdose
  • Fluoxetine poisoning
  • Fluvoxamine overdose
  • Fluvoxamine poisoning
  • Intentional citalopram overdose
  • Intentional citalopram poisoning
  • Intentional fluoxetine overdose
  • Intentional fluoxetine poisoning
  • Intentional fluvoxamine overdose
  • Intentional fluvoxamine poisoning
  • Intentional nefazodone overdose
  • Intentional nefazodone poisoning
  • Intentional paroxetine overdose
  • Intentional paroxetine poisoning
  • Intentional sertraline overdose
  • Intentional sertraline poisoning
  • Nefazodone overdose
  • Nefazodone poisoning
  • Paroxetine overdose
  • Paroxetine poisoning
  • Sertraline overdose
  • Sertraline 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 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

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

CCSR EXT021
External cause codes: intent of injury, self-harm
Default principal diagnosis: inpatient No · outpatient No
CCSR EXT014
External cause codes: poisoning by drug
Default principal diagnosis: inpatient No · outpatient No
CCSR INJ022
Poisoning by drugs, initial encounter
Default principal diagnosis: inpatient No · outpatient No
CCSR MBD012
Suicidal ideation/attempt/intentional self-harm
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Citalopram

    a furancarbonitrile that is one of the selective serotonin reuptake inhibitors used as an antidepressant. the drug is also effective in reducing ethanol uptake in alcoholics and is used in depressed patients who also suffer from tardive dyskinesia in preference to tricyclic antidepressants, which aggravate dyskinesia.

  • Fluoxetine

    the first highly specific serotonin uptake inhibitor. it is used as an antidepressant and often has a more acceptable side-effects profile than traditional antidepressants.

  • Fluvoxamine

    a selective serotonin reuptake inhibitor that is used in the treatment of depression and a variety of anxiety disorders.

  • Zimeldine

    one of the selective serotonin reuptake inhibitors formerly used for depression but was withdrawn worldwide in september 1983 because of the risk of guillain-barre syndrome associated with its use. (from martindale, the extra pharmacopoeia, 29th ed, p385)

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
CitalopramT43.221T43.222T43.223T43.224T43.225T43.226
FemoxetineT43.221T43.222T43.223T43.224T43.225T43.226
FluoxetineT43.221T43.222T43.223T43.224T43.225T43.226
FluvoxamineT43.221T43.222T43.223T43.224T43.225T43.226
IndalpineT43.221T43.222T43.223T43.224T43.225T43.226
ZimeldineT43.221T43.222T43.223T43.224T43.225T43.226

Patient EducationClinical

Poisoning

A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be poisonous if too much is taken. Poisons can include:

Read the full article at MedlinePlus

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

Convert T43.222A to ICD-9-CMHistory

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

ICD-9-CM
969.03 Pois serotinin reuptake
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
E950.3 Poison-psychotropic agt
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T43.222AOverview

Is T43.222A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by selective serotonin reuptake inhibitors, intentional self-harm, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T43.222A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by selective serotonin reuptake inhibitors, intentional self-harm, such as an emergency visit or first evaluation.

What MS-DRG does T43.222A group to?

When poisoning by selective serotonin reuptake inhibitors, intentional self-harm, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 917, 918, with relative weights from 0.8571 to 1.5684 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of T43.222A?

Under the General Equivalence Mappings, poisoning by selective serotonin reuptake inhibitors, intentional self-harm, initial encounter converts to ICD-9-CM 969.03 (pois serotinin reuptake) and E950.3 (poison-psychotropic agt). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.