2027 ICD-10-CM Diagnosis Code T50.6X3SPoisoning by antidotes and chelating agents, assault, sequela

ICD-10-CM Codes›S00–T88›T36-T50›T50

ICD-10-CM T50.6X3S
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

T50.6X3S is a billable ICD-10-CM diagnosis code for poisoning by antidotes and chelating agents, assault, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.

Code Identity

ICD-10-CM Code
T50.6X3S
Billable Status
Yes — Valid for Submission
Code Describes
Poisoning by antidotes and chelating agents, assault, sequela
Short Description
Poisn by antidotes and chelating agents, assault, sequela
Parent Code
Poisoning by antidotes and chelating agents, assault

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
CategoryT50Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances
This CodeT50.6X3SPoisoning by antidotes and chelating agents, assault, sequela

Present on Admission (POA)Billing

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 diuretics and other and unspecified drugs, medicaments and biological substances (T50). 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 T50.6X3S: its own notes plus those printed at T50, 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 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 T50 Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances applies to 342 codes
  • The appropriate 7th character is to be added to each code from category T50
  • 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 T50.6X3S, its category, or a range that includes it.

Use Additional Code 1

These codes say to use an additional code from the note, and T50.6X3S is one of the codes named.

  • G61.1 Serum neuropathy
    code for adverse effect, if applicable, to identify serum (T50.-) names T50.-, 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

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
Alcohol::deterrent NECT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
AntabuseT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Antidote NECT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Calcium::carbimideT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Chelating agent NECT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Cholinesterase reactivatorT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
CysteamineT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Deterrent, alcoholT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Detoxifying agentT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Disodium edetateT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
DisulfiramT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
EDTAT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Ethylenediaminetetra-acetic acidT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Ethylenedinitrilotetra-acetateT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Fytic acid, nonasodiumT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
GlutathioneT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Methylene::blueT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Methylthionine chlorideT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Methylthioninium chlorideT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
NitrefazoleT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Obidoxime chlorideT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
PAM (pralidoxime)T50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
PenicillamineT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Potassium (salts) NEC::ferric hexacyanoferrate (medicinal)T50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Pralidoxime (iodide)T50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Pralidoxime (iodide)::chlorideT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
ProtopamT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Prussian blue::therapeuticT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Pyridine::aldoxime methiodideT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Pyridine::aldoxime methyl chlorideT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Sodium::nitriteT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Sodium::phytateT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Sodium::thiosulfateT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Sodium::versenateT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Tetraethylthiuram disulfideT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
Trisodium hydrogen edetateT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6
VersenateT50.6X1T50.6X2T50.6X3T50.6X4T50.6X5T50.6X6

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 T50.6X3S 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
E969 Late effect assault
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 T50.6X3SOverview

What is the ICD-10 code for poisoning by antidotes and chelating agents, assault, sequela?

The ICD-10-CM code for poisoning by antidotes and chelating agents, assault, sequela is T50.6X3S (sometimes written as T506X3S). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is T50.6X3S (Poisoning by antidotes and chelating agents, assault) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by antidotes and chelating agents, assault, sequela on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What does the 7th character S in T50.6X3S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the poisoning by antidotes and chelating agents, assault itself has resolved, not the original event.

What MS-DRG does T50.6X3S group to?

When poisoning by antidotes and chelating agents, assault, 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 T50.6X3S 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 antidotes and chelating agents, assault, 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.