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ICD-10/T50.911A

T50.911A ICD-10-CM Code: Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional), initial encounter

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0, Appendix B.

  • MS-DRG 917 — POISONING AND TOXIC EFFECTS OF DRUGS WITH MCC (MDC 21)
  • MS-DRG 918 — POISONING AND TOXIC EFFECTS OF DRUGS WITHOUT MCC (MDC 21)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Official Registry Overview & Definition

Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional), initial encounter is a billable ICD-10-CM diagnosis code (T50.911A).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T50.911A in the official ICD-10-CM tabular list.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • 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

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Code First

Underlying conditions that must be sequenced before this code.

  • Code first, 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)

Code Also

Additional codes that may be required to fully describe the encounter.

  • any specific drugs, medicaments and biological substances

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional 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-)

Change history

  • FY2020 — 2019-10-01
    Added to the code set
    Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional), initial encounter
    FY2020 changes

Verify Before Coding

  • Billable — reportable as written.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.

Contextual Map

Every relationship of T50.911A in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

  • S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88) [Hierarchy]
  • T36-T50 — Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances [Hierarchy]
  • T47-T50 — Hormones & Systemic Agents [Hierarchy]

Referenced by Excludes1 notes

  • T38 — Poisoning by, adverse effect of and underdosing of hormones and their synthetic substitutes and antagonists, not elsewhere classified [Excludes1](via T50.9.-): “parathyroid hormones and derivatives (T50.9-)”

Referenced by Use Additional Code instructions

  • G61.1 — Serum neuropathy [Use Additional Code](via T50.-): “code for adverse effect, if applicable, to identify serum (T50.-)”

Clinical classification (CCSR)

  • INJ022 — Poisoning by drugs, initial encounter [CCSR]
  • EXT014 — External cause codes: poisoning by drug [CCSR]
  • EXT020 — External cause codes: intent of injury, accidental/unintentional [CCSR]

Potential MS-DRG

  • DRG 917 — POISONING AND TOXIC EFFECTS OF DRUGS WITH MCC [MS-DRG]: “POISONING AND TOXIC EFFECTS OF DRUGS WITH MCC (MDC 21)”
  • DRG 918 — POISONING AND TOXIC EFFECTS OF DRUGS WITHOUT MCC [MS-DRG]: “POISONING AND TOXIC EFFECTS OF DRUGS WITHOUT MCC (MDC 21)”

Drugs & chemicals

  • Multiple unspecified drugs, medicaments and biological substances — Multiple unspecified drugs, medicaments and biological substances — Poisoning, Accidental (unintentional) [Drug table]: “Multiple unspecified drugs, medicaments and biological substances (Poisoning, Accidental (unintentional))”

Nearest codes (40)

  • T50 — Poisoning by, adverse effect of and underdosing of diuretics and other and unspecified drugs, medicaments and biological substances [Sibling]
  • T50.902D — Poisoning by unspecified drugs, medicaments and biological substances, intentional self-harm, subsequent encounter [Sibling]
  • T50.902S — Poisoning by unspecified drugs, medicaments and biological substances, intentional self-harm, sequela [Sibling]
  • T50.903 — Poisoning by unspecified drugs, medicaments and biological substances, assault [Sibling]
  • T50.903A — Poisoning by unspecified drugs, medicaments and biological substances, assault, initial encounter [Sibling]
  • T50.903D — Poisoning by unspecified drugs, medicaments and biological substances, assault, subsequent encounter [Sibling]
  • T50.903S — Poisoning by unspecified drugs, medicaments and biological substances, assault, sequela [Sibling]
  • T50.904 — Poisoning by unspecified drugs, medicaments and biological substances, undetermined [Sibling]
  • and 32 more

Change history

  • FY2020 — Added to the code set [Change history]

Referenced by Other Codes

Clinical classification (AHRQ CCSR):INJ022 — Poisoning by drugs, initial encounter (default); EXT014 — External cause codes: poisoning by drug; EXT020 — External cause codes: intent of injury, accidental/unintentional.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Potential MS-DRG Relationships (FY2026)

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Named in the grouper logic of 2 MS-DRGs: DRG 917 (MDC 21), DRG 918 (MDC 21).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Official ICD-10-CM tabular notes on other codes that name T50.911A or its code family.

1 Excludes1 notes: T38 (via T50.9.-).

1 Use Additional Code instructions: G61.1 (via T50.-).

Frequently Asked Questions (FAQ) & Clinical Guidance

Does T50.911A require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category T50.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T50.911A in its code family, with their registry titles.

  • T50.906A — Underdosing of unspecified drugs, medicaments and biological substances, initial encounter
  • T50.906D — Underdosing of unspecified drugs, medicaments and biological substances, subsequent encounter
  • T50.906S — Underdosing of unspecified drugs, medicaments and biological substances, sequela
  • T50.91 — Poisoning by, adverse effect of and underdosing of multiple unspecified drugs, medicaments and biological substances
  • T50.911 — Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional)
  • T50.911D — Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional), subsequent encounter
  • T50.911S — Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional), sequela
  • T50.912 — Poisoning by multiple unspecified drugs, medicaments and biological substances, intentional self-harm
  • T50.912A — Poisoning by multiple unspecified drugs, medicaments and biological substances, intentional self-harm, initial encounter
  • T50.912D — Poisoning by multiple unspecified drugs, medicaments and biological substances, intentional self-harm, subsequent encounter

View all codes in the T50 family

Associated Substances (1)

Substances from the official ICD-10-CM Table of Drugs and Chemicals that map to this code.

  • Multiple unspecified drugs, medicaments and biological substances