Coding and coverage · ICD-10-CM

T56

T56.1 Toxic effects of mercury and its compounds

Not billable (header)Chapter 19

This code needs a 7th character (use X as a placeholder for missing characters).

Codes under this one

  • T56.1X Toxic effects of mercury and its compoundsHeader

Instructional notes

Chapter 19

Excludes2Not included here: the patient may have both; report both when both are present.
Use additional codeAdd a second code for the full picture.
  • code to identify any retained foreign body, if applicable (Z18.-)
Notes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

T56

Excludes1Not coded here: never report with this code, except when the two conditions are unrelated.
  • arsenic and its compounds (T57.0)
  • manganese and its compounds (T57.2)
Use additional codeAdd a second code for the full picture.
  • code to identify any retained metal foreign body, if applicable (Z18.0-, T18.1-)
Includes
  • toxic effects of fumes and vapors of metals
  • toxic effects of metals from all sources, except medicinal substances
7th charactersThe appropriate 7th character is to be added to each code from category T56
  • A initial encounter
  • D subsequent encounter
  • S sequela

Chapter 19: Injury, poisoning and certain other consequences of external causes · T07-T88 Injury, poisoning and certain other consequences of external causes (T07-T88)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.