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T50.91 ICD-10-CM Code: Poisoning by, adverse effect of and underdosing of multiple unspecified drugs, medicaments and biological substances

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Official Registry Overview & Definition

Poisoning by, adverse effect of and underdosing of multiple unspecified drugs, medicaments and biological substances is a non-billable ICD-10-CM category code (T50.91). A more specific billable subcode must be selected for claims submission.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T50.91 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

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Multiple drug ingestion NOS

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-)

Frequently Compared Codes

The official Excludes notes on T50.91 name these codes. Each comparison page covers when the two can — or must not — be reported together.

Change history

  • FY2020 — 2019-10-01
    Added to the code set
    Poisoning by, adverse effect of and underdosing of multiple unspecified drugs, medicaments and biological substances
    FY2020 changes

Verify Before Coding

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

Relationships & Classification

Official ICD-10-CM tabular notes on other codes that name T50.91 or its code family.

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

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

Contextual Map

Every relationship of T50.91 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]

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-)” · check together

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.-)” · check together

Nearest codes (40)

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

Change history

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

Frequently Asked Questions (FAQ) & Clinical Guidance

Can T50.91 be billed directly?

No. T50.91 (Poisoning by, adverse effect of and underdosing of multiple unspecified drugs, medicaments and biological substances) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Does T50.91 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 T50.91 in its code family, with their registry titles.

  • T50.905S — Adverse effect of unspecified drugs, medicaments and biological substances, sequela
  • T50.906 — Underdosing of unspecified drugs, medicaments and biological substances
  • 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
  • T50.911 — Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional)
  • T50.911A — Poisoning by multiple unspecified drugs, medicaments and biological substances, accidental (unintentional), initial encounter
  • 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

View all codes in the T50 family