2026 ICD-10-CM Diagnosis Code T56.2X3SToxic effect of chromium and its compounds, assault, sequela
T56.2X3S is a billable ICD-10-CM diagnosis code for toxic effect of chromium and its compounds, assault, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
T56.2X3S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
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 T56.2X3S to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T56.2X3SOverview
Is T56.2X3S (Toxic effect of chromium and its compounds, assault) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report toxic effect of chromium and its compounds, assault, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T56.2X3S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the toxic effect of chromium and its compounds, assault itself has resolved, not the original event.
What MS-DRG does T56.2X3S group to?
When toxic effect of chromium and its compounds, assault, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.
Is T56.2X3S exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for toxic effect of chromium and its compounds, assault, sequela on inpatient claims.
What is the ICD-9 equivalent of T56.2X3S?
Under the General Equivalence Mappings, toxic effect of chromium and its compounds, assault, sequela converts to ICD-9-CM 909.1 (late eff nonmed substanc). 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.
