Is ICD-10-CM code T65 billable?

No, T65 (Toxic effect of other and unspecified substances) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code T65 belong to?

T65 belongs to Chapter 19 of the ICD-10-CM tabular list: S00–T88 (Injury, Poisoning and Certain Other Consequences of External Causes).

T65Not billable, use a more specific code below

Toxic effect of other and unspecified substances

In Toxic effects of substances chiefly nonmedicinal as to source (T51-T65), chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes

192 billable codes under T65: none are a CC or MCC; 15 map to HCC 155 (Major Depression, Moderate or Severe, without Psychosis).An HCC counts toward a Medicare Advantage patient's risk score.

Instructional notes

Also applies, from Toxic effects of substances chiefly nonmedicinal as to source (T51-T65)

These notes sit on T51-T65 and apply to every code under it, including T65.

Excludes1: not coded here, use a different code

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

Use additional code: add a second code for this, listed after this one

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.-)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Section I.C.19.e Adverse Effects, Poisoning, Underdosing and Toxic Effects (page 82), covers T65
For adverse effects, code the effect first, then T36-T50 with character 5. Sequence poisonings (unknown intent coded accidental) and toxic effects (T51-T65) first; underdosing (character 6) is never first-listed.

All codes under T65

T65 can't be used on a claim. Pick a billable code below; grey headings group them.

T65 MS-DRGs

As the principal diagnosis, the billable codes under T65 group to MS-DRG 917, 918, 922, 923, 949, or 950 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

DRG 917 Poisoning and Toxic Effects of Drugs with MCC (64 of 192 codes)
DRG 918 Poisoning and Toxic Effects of Drugs without MCC (64 of 192 codes)
DRG 922 Other Injury, Poisoning and Toxic Effect Diagnoses with MCC (64 of 192 codes)
DRG 923 Other Injury, Poisoning and Toxic Effect Diagnoses without MCC (64 of 192 codes)
DRG 949 Aftercare with CC/MCC (64 of 192 codes)
DRG 950 Aftercare without CC/MCC (64 of 192 codes)

Other codes that refer to T65

Notes on these codes point to T65.

D61.2 Code First: if applicable, toxic effects of substances chiefly nonmedicinal as to source (T51-T65)
D64.2 Code First: poisoning due to drug or toxin, if applicable (T36-T65 with fifth or sixth character 1-4)
E03.2 Code First: poisoning due to drug or toxin, if applicable (T36-T65 with fifth or sixth character 1-4)
E09 Code First: poisoning due to drug or toxin, if applicable (T36-T65 with fifth or sixth character 1-4)
F02 Code First: intoxications (T36-T65)
G21.2 Code First: (T51-T65) to identify external agent
G62.2 Code First: (T51-T65) to identify toxic agent
G70.1 Code First: (T51-T65) to identify toxic agent
G72.2 Code First: (T51-T65) to identify toxic agent
G92.8 Code First: poisoning due to drug or toxin, if applicable, (T36-T65 with fifth or sixth character 1-4)
G92.9 Code First: poisoning due to drug or toxin, if applicable, (T36-T65 with fifth or sixth character 1-4)
H10.21 Code First: (T51-T65) to identify chemical and intent
H35.38 Code First: poisoning due to drug or toxin, if applicable (T36-T65 with fifth or sixth character 1-4)
H46.3 Code First: (T51-T65) to identify cause
H91.0 Code First: poisoning due to drug or toxin, if applicable (T36-T65 with fifth or sixth character 1-4)
I42.7 Code First: poisoning due to drug or toxin, if applicable (T36-T65 with fifth or sixth character 1-4)
J68 Code First: (T51-T65) to identify cause
J69.1 Code First: (T51-T65) to identify substance
J69.8 Code First: (T51-T65) to identify substance
J70.8 Code First: (T51-T65) to identify the external agent

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

Poisoning

A poison is any substance that is harmful to your body. You might swallow it, inhale it, inject it, or absorb it through your skin. Any substance can be poisonous if too much is taken. Poisons can include:

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.