T65 – Toxic effect of other and unspecified substances

ICD-10-CM 2027 diagnosis code · Toxic effects of substances chiefly nonmedicinal as to source

Non-billable header

ICD-10-CM code T65

Code: T65 (claims format: T65)
Description: Toxic effect of other and unspecified substances
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 19. Injury, poisoning and certain other consequences of external causes (S00-T88)
Block: T51-T65 Toxic effects of substances chiefly nonmedicinal as to source

Billable codes under T65

T65 is a header code and cannot be used on claims. Choose the most specific code:

T65.0 – Toxic effect of cyanidesHeader (more codes below)
T65.1 – Toxic effect of strychnine and its saltsHeader (more codes below)
T65.2 – Toxic effect of tobacco and nicotineHeader (more codes below)
T65.3 – Toxic effect of nitroderivatives and aminoderivatives of benzene and its homologuesHeader (more codes below)
T65.4 – Toxic effect of carbon disulfideHeader (more codes below)
T65.5 – Toxic effect of nitroglycerin and other nitric acids and estersHeader (more codes below)
T65.6 – Toxic effect of paints and dyes, not elsewhere classifiedHeader (more codes below)
T65.8 – Toxic effect of other specified substancesHeader (more codes below)
T65.9 – Toxic effect of unspecified substanceHeader (more codes below)

7th character values

Codes in this category need a 7th character to describe the encounter or episode of care (use placeholder X for empty positions).

Character	Meaning
`A`	initial encounter
`D`	subsequent encounter
`S`	sequela

Notes for T65

7th character note:

The appropriate 7th character is to be added to each code from category T65

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block T51-T65

Excludes1 (not coded here):

contact with and (suspected) exposure to toxic substances (Z77.-)

Use additional code:

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.-)

Notes:

When no intent is indicated code to accidental. Undetermined intent is only for use when there is specific documentation in the record that the intent of the toxic effect cannot be determined.

Frequently asked questions

What is ICD-10 code T65?

T65 is the ICD-10-CM code for toxic effect of other and unspecified substances, in the block T51-T65 (Toxic effects of substances chiefly nonmedicinal as to source).

Is T65 a billable code?

No. T65 is a header code with more specific child codes; report one of the billable codes listed above.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.