2026 ICD-10-CM Diagnosis Code T56.2X2AToxic effect of chromium and its compounds, intentional self-harm, initial encounter

ICD-10-CM CodesS00–T88T51-T65T56

ICD-10-CM T56.2X2A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T56.2X2A is a billable ICD-10-CM diagnosis code for toxic effect of chromium and its compounds, intentional self-harm, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, self-harm; External cause codes: poisoning by non-drug; and Suicidal ideation/attempt/intentional self-harm.

Code Identity

ICD-10-CM Code
T56.2X2A
Billable Status
Yes — Valid for Submission
Code Describes
Toxic effect of chromium and its compounds, intentional self-harm, initial encounter
Short Description
Toxic effect of chromium and its compounds, self-harm, init
Parent Code
Toxic effect of chromium and its compounds, intentional self-harm

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT51-T65Toxic effects of substances chiefly nonmedicinal as to source
CategoryT56Toxic effect of metals
This CodeT56.2X2AToxic effect of chromium and its compounds, intentional self-harm, initial encounter

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.

CCSR EXT021
External cause codes: intent of injury, self-harm
Default principal diagnosis: inpatient No · outpatient No
CCSR EXT015
External cause codes: poisoning by non-drug
Default principal diagnosis: inpatient No · outpatient No
CCSR MBD012
Suicidal ideation/attempt/intentional self-harm
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INJ023
Toxic effects, initial encounter
Default principal diagnosis: inpatient No · outpatient No

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.

SubstanceAccidentalSelf-harmAssaultUndeter­minedAdverse
Effect
Under­dosing
ChromateT56.2X1T56.2X2T56.2X3T56.2X4
Chromate::dust or mistT56.2X1T56.2X2T56.2X3T56.2X4
Chromate::lead [See Also: lead]T56.2X1T56.2X2T56.2X3T56.2X4
Chromate::lead [See Also: lead]::paintT56.2X1T56.2X2T56.2X3T56.2X4
ChromicT56.2X1T56.2X2T56.2X3T56.2X4
Chromic::acidT56.2X1T56.2X2T56.2X3T56.2X4
Chromic::acid::dust or mistT56.2X1T56.2X2T56.2X3T56.2X4
Chromic::phosphate 32PT56.2X1T56.2X2T56.2X3T56.2X4
ChromiumT56.2X1T56.2X2T56.2X3T56.2X4
Chromium::compoundsT56.2X1T56.2X2T56.2X3T56.2X4
Chromium::sesquioxideT56.2X1T56.2X2T56.2X3T56.2X4
Chromyl chlorideT56.2X1T56.2X2T56.2X3T56.2X4

Convert T56.2X2A to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
985.6 Toxic effect chromium
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
E950.9 Poison-solid/liquid NEC
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T56.2X2AOverview

Is T56.2X2A a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report toxic effect of chromium and its compounds, intentional self-harm, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T56.2X2A 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, intentional self-harm, such as an emergency visit or first evaluation.

What MS-DRG does T56.2X2A group to?

When toxic effect of chromium and its compounds, intentional self-harm, 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 T56.2X2A?

Under the General Equivalence Mappings, toxic effect of chromium and its compounds, intentional self-harm, initial encounter converts to ICD-9-CM 985.6 (toxic effect chromium) and E950.9 (poison-solid/liquid 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.