T56.1X1 is the authoritative medical code for Toxic effect of mercury and its compounds, accidental (unintentional). This classification is used in medical billing and clinical recording to specify the clinical criteria for toxic effect of mercury and its compounds, accidental (unintentional) (ICD-10-CM T56.1X1), ensuring healthcare documentation aligns with 2026 federal coding standards.
Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.
Official Registry Overview & Definition
Toxic effect of mercury and its compounds, accidental (unintentional) is a non-billable ICD-10-CM category code T56.1X1. A more specific billable subcode must be selected for claims submission. Includes: toxic effects of fumes and vapors of metals; toxic effects of metals from all sources, except medicinal substances. Inclusion terms: Toxic effects of mercury and its compounds NOS. Excludes1 (not coded here): arsenic and its compounds T57.0; manganese and its compounds T57.2; contact with and suspected exposure to toxic substances Z77.-. Use additional code: code to identify any retained metal foreign body, if applicable (Z18.0-, T18.1-); code(s):; for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents J60-J70; personal history of foreign body fully removed Z87.821; to identify any retained foreign body, if applicable Z18.-. 7th character: The appropriate 7th character is to be added to each code from category T56.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for T56.1X1 in the official ICD-10-CM tabular list.
Includes
Conditions the official ICD-10-CM tabular list includes under this code.
- toxic effects of fumes and vapors of metals
- toxic effects of metals from all sources, except medicinal substances
Inclusion Terms
Alternative terms the tabular list files under this code.
- Toxic effects of mercury and its compounds NOS
Excludes1 — Not Coded Here
Conditions that can never be reported with this code; the two are mutually exclusive.
- arsenic and its compounds T57.0
- manganese and its compounds T57.2
- contact with and suspected exposure to toxic substances Z77.-
Use Additional Code
Supplementary codes the tabular list directs you to add.
- code to identify any retained metal foreign body, if applicable (Z18.0-, T18.1-)
- code(s):
- for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents J60-J70
- personal history of foreign body fully removed Z87.821
- to identify any retained foreign body, if applicable Z18.-
Frequently Asked Questions (FAQ) & Clinical Guidance
Can T56.1X1 be billed directly?
No. T56.1X1 (Toxic effect of mercury and its compounds, accidental (unintentional)) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Does T56.1X1 require a 7th character?
Yes. The appropriate 7th character is to be added to each code from category T56.
What can't be coded together with T56.1X1?
Per Excludes1 instructions, T56.1X1 must not be reported with: arsenic and its compounds (T57.0); manganese and its compounds (T57.2); contact with and (suspected) exposure to toxic substances (Z77.-).
Is an additional code needed with T56.1X1?
Use additional code(s) to specify: code to identify any retained metal foreign body, if applicable (Z18.0-, T18.1-); code(s):; for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents (J60-J70); personal history of foreign body fully removed (Z87.821).
What conditions are included under T56.1X1?
Toxic effect of mercury and its compounds, accidental (unintentional) includes: Toxic effects of mercury and its compounds NOS.
Codes in This Family (40)
Official ICD-10-CM classifications in the same code family as T56.1X1, with their registry titles.
- T56 — Toxic effect of metals
- T56.0 — Toxic effects of lead and its compounds
- T56.0X — Toxic effects of lead and its compounds
- T56.0X1 — Toxic effect of lead and its compounds, accidental (unintentional)
- T56.0X1A — Toxic effect of lead and its compounds, accidental (unintentional), initial encounter
- T56.0X1D — Toxic effect of lead and its compounds, accidental (unintentional), subsequent encounter
- T56.0X1S — Toxic effect of lead and its compounds, accidental (unintentional), sequela
- T56.0X2 — Toxic effect of lead and its compounds, intentional self-harm
- T56.0X2A — Toxic effect of lead and its compounds, intentional self-harm, initial encounter
- T56.0X2D — Toxic effect of lead and its compounds, intentional self-harm, subsequent encounter
- T56.0X2S — Toxic effect of lead and its compounds, intentional self-harm, sequela
- T56.0X3 — Toxic effect of lead and its compounds, assault
- T56.0X3A — Toxic effect of lead and its compounds, assault, initial encounter
- T56.0X3D — Toxic effect of lead and its compounds, assault, subsequent encounter
- T56.0X3S — Toxic effect of lead and its compounds, assault, sequela
- T56.0X4 — Toxic effect of lead and its compounds, undetermined
- T56.0X4A — Toxic effect of lead and its compounds, undetermined, initial encounter
- T56.0X4D — Toxic effect of lead and its compounds, undetermined, subsequent encounter
- T56.0X4S — Toxic effect of lead and its compounds, undetermined, sequela
- T56.1 — Toxic effects of mercury and its compounds
- T56.1X — Toxic effects of mercury and its compounds
- T56.1X1A — Toxic effect of mercury and its compounds, accidental (unintentional), initial encounter
- T56.1X1D — Toxic effect of mercury and its compounds, accidental (unintentional), subsequent encounter
- T56.1X1S — Toxic effect of mercury and its compounds, accidental (unintentional), sequela
- T56.1X2 — Toxic effect of mercury and its compounds, intentional self-harm
- T56.1X2A — Toxic effect of mercury and its compounds, intentional self-harm, initial encounter
- T56.1X2D — Toxic effect of mercury and its compounds, intentional self-harm, subsequent encounter
- T56.1X2S — Toxic effect of mercury and its compounds, intentional self-harm, sequela
- T56.1X3 — Toxic effect of mercury and its compounds, assault
- T56.1X3A — Toxic effect of mercury and its compounds, assault, initial encounter
- T56.1X3D — Toxic effect of mercury and its compounds, assault, subsequent encounter
- T56.1X3S — Toxic effect of mercury and its compounds, assault, sequela
- T56.1X4 — Toxic effect of mercury and its compounds, undetermined
- T56.1X4A — Toxic effect of mercury and its compounds, undetermined, initial encounter
- T56.1X4D — Toxic effect of mercury and its compounds, undetermined, subsequent encounter
- T56.1X4S — Toxic effect of mercury and its compounds, undetermined, sequela
- T56.2 — Toxic effects of chromium and its compounds
- T56.2X — Toxic effects of chromium and its compounds
- T56.2X1 — Toxic effect of chromium and its compounds, accidental (unintentional)
- T56.2X1A — Toxic effect of chromium and its compounds, accidental (unintentional), initial encounter
Associated Substances (2)
Substances from the official ICD-10-CM Table of Drugs and Chemicals that map to this code.
- Fulminate of mercury
- Mercury, mercurial, mercuric, mercurousNEC (compounds) (cyanide) (fumes) (nonmedicinal) (vapor)
Related Codes & Numerical Sequence (Crawl Map)
Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:
ICD Code T54.1X1
Toxic effect of other corrosive organic compounds, accidental (unintentional)
ICD Code T57.1X1
Toxic effect of phosphorus and its compounds, accidental (unintentional)
ICD Code T60.1X1
Toxic effect of halogenated insecticides, accidental (unintentional)