2026 ICD-10-CM Diagnosis Code T56.2X1AToxic effect of chromium and its compounds, accidental (unintentional), initial encounter
T56.2X1A is a billable ICD-10-CM diagnosis code for toxic effect of chromium and its compounds, accidental (unintentional), 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 toxic effect of chromium. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, accidental/unintentional; 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.
- Toxic effect of chromium
- Ulcer of skin caused by chromium
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
Adenosine Triphosphate
an adenine nucleotide containing three phosphate groups esterified to the sugar moiety. in addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.Chromium
a trace element that plays a role in glucose metabolism. it has the atomic symbol cr, atomic number 24, and atomic weight 52. according to the fourth annual report on carcinogens (ntp85-002,1985), chromium and some of its compounds have been listed as known carcinogens.Chromium Alloys
specific alloys not less than 85% chromium and nickel or cobalt, with traces of either nickel or cobalt, molybdenum, and other substances. they are used in partial dentures, orthopedic implants, etc.Chromium Compounds
inorganic compounds that contain chromium as an integral part of the molecule.Chromium Isotopes
stable chromium atoms that have the same atomic number as the element chromium, but differ in atomic weight. cr-50, 53, and 54 are stable chromium isotopes.Chromium Radioisotopes
unstable isotopes of chromium that decay or disintegrate emitting radiation. cr atoms with atomic weights of 46-49, 51, 55, and 56 are radioactive chromium isotopes.Edetic Acid
a chelating agent that sequesters a variety of polyvalent cations such as calcium. it is used in pharmaceutical manufacturing and as a food additive.Oxalic Acid
a strong dicarboxylic acid occurring in many plants and vegetables. it is produced in the body by metabolism of glyoxylic acid or ascorbic acid. it is not metabolized but excreted in the urine. it is used as an analytical reagent and general reducing agent.
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 |
|---|---|---|---|---|---|---|
| Chromate | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromate::dust or mist | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromate::lead [See Also: lead] | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromate::lead [See Also: lead]::paint | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromic | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromic::acid | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromic::acid::dust or mist | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromic::phosphate 32P | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromium | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromium::compounds | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromium::sesquioxide | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
| Chromyl chloride | T56.2X1 | T56.2X2 | T56.2X3 | T56.2X4 | – | – |
Convert T56.2X1A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T56.2X1AOverview
Is T56.2X1A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report toxic effect of chromium and its compounds, accidental (unintentional), initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T56.2X1A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for toxic effect of chromium and its compounds, accidental (unintentional), such as an emergency visit or first evaluation.
What MS-DRG does T56.2X1A group to?
When toxic effect of chromium and its compounds, accidental (unintentional), 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 T56.2X1A?
Under the General Equivalence Mappings, toxic effect of chromium and its compounds, accidental (unintentional), initial encounter converts to ICD-9-CM 985.6 (toxic effect chromium) and E866.4 (acc poison-metals 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.
