Is ICD-10-CM code T66-T78 billable?

No, T66-T78 (Other and unspecified effects of external causes (T66-T78)) 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 T66-T78 belong to?

T66-T78 belongs to Chapter 19 of the ICD-10-CM tabular list: S00–T88 (Injury, Poisoning and Certain Other Consequences of External Causes).

T66-T78Not billable, use a more specific code below

Other and unspecified effects of external causes (T66-T78)

chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes

Instructional notes

Code also: add a code for this too, order depends on the encounter

if applicable, place of occurrence, such as:
highway rest stop (Y92.523)
school (private) (public) (state) as the place of occurrence of the external cause (Y92.21-)
service areas as the place of occurrence of the external cause (Y92.52-)
single-family non-institutional (private) house as the place of occurrence of the external cause (Y92.01-)
transport vehicle as the place of occurrence of the external cause (Y92.81-)

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.

Covers 7th character use and coding of injuries, fractures, burns, drug and toxic effects, abuse and neglect, and complications of care (S00-T88).

Application of 7th Characters in Chapter 19 (page 77)
Coding of Injuries (page 78)
Coding of Traumatic Fractures (page 79)
Coding of Burns and Corrosions (page 80)
Adverse Effects, Poisoning, Underdosing and Toxic Effects (page 82)
Adult and child abuse, neglect and other maltreatment (page 85)
Complications of care (page 85)

Read Section I.C.19 (page 77)

Codes under T66-T78

T66-T78 can't be used on a claim. Pick a billable code below; grey headings group them.

T66-T78 MS-DRGs

This code does not group to an MS-DRG as a principal diagnosis.

About the condition

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

Radiation Exposure

Radiation is energy. It travels in the form of energy waves or high-speed particles. Radiation can occur naturally or be man-made. There are two types: