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ICD-10/T56.91XA

T56.91XA ICD-10-CM Code: Toxic effect of unspecified metal, 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 (FY2026), 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.

Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.

Official Registry Overview & Definition

Toxic effect of unspecified metal, accidental (unintentional), initial encounter is a billable ICD-10-CM diagnosis code (T56.91A).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T56.91XA in the official ICD-10-CM tabular list.

Includes

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

  • toxic effects of fumes and vapors of metals
  • toxic effects of metals from all sources, except medicinal substances

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • arsenic and its compounds (T57.0)
  • manganese and its compounds (T57.2)
  • contact with and (suspected) exposure to toxic substances (Z77.-)

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code to identify any retained metal foreign body, if applicable (Z18.0-, T18.1-)
  • Use additional code(s):
  • for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents (J60-J70)
  • personal history of foreign body fully removed (Z87.821)
  • to identify any retained foreign body, if applicable (Z18.-)

Frequently Asked Questions (FAQ) & Clinical Guidance

Does T56.91XA require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category T56.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T56.91XA in its code family, with their registry titles.

  • T56.894A — Toxic effect of other metals, undetermined, initial encounter
  • T56.894D — Toxic effect of other metals, undetermined, subsequent encounter
  • T56.894S — Toxic effect of other metals, undetermined, sequela
  • T56.9 — Toxic effects of unspecified metal
  • T56.91 — Toxic effect of unspecified metal, accidental (unintentional)
  • T56.91XD — Toxic effect of unspecified metal, accidental (unintentional), subsequent encounter
  • T56.91XS — Toxic effect of unspecified metal, accidental (unintentional), sequela
  • T56.92 — Toxic effect of unspecified metal, intentional self-harm
  • T56.92XA — Toxic effect of unspecified metal, intentional self-harm, initial encounter
  • T56.92XD — Toxic effect of unspecified metal, intentional self-harm, subsequent encounter

View all codes in the T56 family