2026 ICD-10-CM Diagnosis Code T56.894AToxic effect of other metals, undetermined, initial encounter
T56.894A is a billable ICD-10-CM diagnosis code for toxic effect of other metals, undetermined, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 917 through 918. Coders also document this condition as allergic reaction to nickel. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, undetermined; External cause codes: poisoning by non-drug; and Toxic effects, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Allergic reaction to nickel
- Contact dermatitis caused by nickel
- Contact hypersensitivity reaction
- Silver poisoning
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Toxic effect of metals (T56). 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 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
gamma-Aminobutyric Acid
the most common inhibitory neurotransmitter in the central nervous system.Lithium
an element in the alkali metals family. it has the atomic symbol li, atomic number 3, and atomic weight [6.938; 6.997]. salts of lithium are used in treating bipolar disorder.Lithium Carbonate
a lithium salt, classified as a mood-stabilizing agent. lithium ion alters the metabolism of biogenic monoamines in the central nervous system, and affects multiple neurotransmission systems.Lithium Chloride
a salt of lithium that has been used experimentally as an immunomodulator.Lithium Compounds
inorganic compounds that contain lithium as an integral part of the molecule.Niacin
a water-soluble vitamin of the b complex occurring in various animal and plant tissues. it is required by the body for the formation of coenzymes nad and nadp. it has pellagra-curative, vasodilating, and antilipemic properties.Tellurium
an element that is a member of the chalcogen family. it has the atomic symbol te, atomic number 52, and atomic weight 127.60. it has been used as a coloring agent and in the manufacture of electrical equipment. exposure may cause nausea, vomiting, and cns depression.Nitrogenase
an enzyme system that catalyzes the fixing of nitrogen in soil bacteria and blue-green algae (cyanobacteria). ec 1.18.6.1.Vanadium
a metallic element with the atomic symbol v, atomic number 23, and atomic weight 50.94. it is used in the manufacture of vanadium steel. prolonged exposure can lead to chronic intoxication caused by absorption usually via the lungs.Vanadium Compounds
inorganic compounds that contain vanadium as an integral part of the molecule.
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.
| Substance | Accidental | Self-harm | Assault | Undetermined | Adverse Effect | Underdosing |
|---|---|---|---|---|---|---|
| Antimony (compounds) (vapor) NEC | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Antimony (compounds) (vapor) NEC::anti-infectives | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Antimony (compounds) (vapor) NEC::dimercaptosuccinate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Antimony (compounds) (vapor) NEC::hydride | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Antimony (compounds) (vapor) NEC::pesticide (vapor) | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Antimony (compounds) (vapor) NEC::potassium (sodium) tartrate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Antimony (compounds) (vapor) NEC::sodium dimercaptosuccinate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Antimony (compounds) (vapor) NEC::tartrated | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Brass (fumes) | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Cobalt (nonmedicinal) (fumes) (industrial) | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Cobalt (nonmedicinal) (fumes) (industrial)::medicinal (trace) (chloride) | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Golden sulfide of antimony | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Lithium | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Lithium::gluconate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Lithium::salts (carbonate) | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::carbonate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::citrate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::hydroxide | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::oxide | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::peroxide | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::salicylate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::silicofluoride | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::sulfate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::thiosulfate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Magnesium NEC::trisilicate | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Nickel (carbonyl) (tetra-carbonyl) (fumes) (vapor) | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Nickelocene | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Selenium NEC | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Selenium NEC::disulfide or sulfide | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Selenium NEC::fumes | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Selenium NEC::sulfide | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Stibine | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Tellurium | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Tellurium::fumes | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Titanium (compounds) (vapor) | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Titanium (compounds) (vapor)::dioxide | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Titanium (compounds) (vapor)::ointment | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Titanium (compounds) (vapor)::oxide | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Titanium (compounds) (vapor)::tetrachloride | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Titanocene | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
| Vanadium | T56.891 | T56.892 | T56.893 | T56.894 | – | – |
Convert T56.894A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T56.894AOverview
Is T56.894A (Toxic effect of other metals, undetermined) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report toxic effect of other metals, undetermined, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T56.894A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for toxic effect of other metals, undetermined, such as an emergency visit or first evaluation.
What MS-DRG does T56.894A group to?
When toxic effect of other metals, undetermined, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 917, 918, with relative weights from 0.8571 to 1.5684 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of T56.894A?
Under the General Equivalence Mappings, toxic effect of other metals, undetermined, initial encounter converts to ICD-9-CM 985.8 (toxic effect metals NEC) and E980.9 (undeter pois-sol/liq NEC). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
