T56.91 Toxic effect of unspecified metal, accidental (unintentional)

ICD-10-CM T56.91: Toxic effect of unspecified metal, accidental (unintentional)

ICD-10-CM code T56.91 represents the accidental or unintentional toxic effect of an unspecified metal, classified under the broader parent category of unspecified metal toxic effects. This active diagnosis concept is identified as an injury or poisoning event. The supplied sources establish its official terminology and structural hierarchy, though specific clinical parameters require further documentation. 1 4

Plain-language overview

Code T56.91 identifies an accidental or unintentional toxic effect caused by an unspecified metal, serving as a diagnostic label for this specific type of poisoning injury. 1

What this code represents

The terminology record classifies T56.91 with the semantic type of Injury or Poisoning, placing it within a clinical classification for harmful substance exposures. 1

T56.91 is an active concept that holds no narrower child concepts, meaning it currently functions as a specific endpoint within this branch of the terminology hierarchy. 1

Coding details

In the ICD-10-CM hierarchy, T56.91 is a direct child of the parent concept T56.9, which encompasses the toxic effects of unspecified metals overall without specifying intent. 1

Documentation considerations

The terminology record for T56.91 specifies the accidental intent and unspecified metal within its official preferred name, providing the exact descriptive elements for this diagnostic label. 1

Coverage and utilization context

A Medicare billing and coding article for oximetry services includes the T56.91 code in an associated list of diagnoses without detailing specific coverage criteria. 4

What the sources add

The National Cancer Institute terminology record provides the official active status and exact preferred name for T56.91, whereas the Medicare article demonstrates its appearance in administrative billing contexts. 1 4

Clinical context

Clinical literature notes that acute toxicity from substances like iron involves local gastrointestinal injury and systemic toxicity, often resulting from intentional or accidental ingestion. 2

Sources

1. ICD-10-CM T56.91 terminology record — National Cancer Institute Enterprise Vocabulary Services; accessed 2026-07-27.
2. Bookshelf — ncbi.nlm.nih.gov; accessed 2026-07-27.
3. Article - Billing and Coding: Heavy Metal Testing (A56767) — cms.gov; accessed 2026-07-27.
4. Article - Billing and Coding: Oximetry Services (A57205) — cms.gov; accessed 2026-07-27.