T66Non-billableSave
T66 - Radiation sickness, unspecified
ICD-10-CM Chapter 19: Injury, poisoning and certain other consequences of external causes · T66-T78 Other and unspecified effects of external causes (T66-T78) · Top-level category · FY2027
Coding Guidance
T66 requires a 7th character. Report the code below that matches the documentation, for example A for initial encounter, D for subsequent encounter, S for sequela.
7th Character
The appropriate 7th character is to be added to code T66
Includes, Excludes and Coding Notes
Excludes 1 — Not Coded HereFrom T66
Mutually exclusive: these conditions are never reported together with this code.
- specified adverse effects of radiation, such as:
- burns (T20-T31)
- leukemia (C91-C95)
- radiation gastroenteritis and colitis (K52.0)
- radiation pneumonitis (J70.0)
- radiation related disorders of the skin and subcutaneous tissue (L55-L59)
- sunburn (L55.-)
Code AlsoFrom T66-T78 Other and unspecified effects of external causes (T66-T78)
Report an additional code when both conditions apply.
- , 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-)
Excludes 2 — Not Included HereFrom Chapter S00-T88
Not part of this code; report both codes when the patient has both conditions.
- birth trauma (P10-P15)
- obstetric trauma (O70-O71)
Use Additional CodeFrom Chapter S00-T88
Add a secondary code to identify the associated condition or cause when it is documented.
- code to identify any retained foreign body, if applicable (Z18.-)
NotesFrom Chapter S00-T88
Instructional notes from the ICD-10-CM tabular list.
- 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.
Chapter Information
Chapter 19: Injury, poisoning and certain other consequences of external causes
Range: S00-T88
View full chapterRelated ICD-10 Codes
More specific codes for T66
Other categories in this chapter
Codes at the same level as T66
- Superficial injury of headS00
- Open wound of headS01
- Fracture of skull and facial bonesS02
- Dislocation and sprain of joints and ligaments of headS03
- Injury of cranial nerveS04
- Injury of eye and orbitS05
- Intracranial injuryS06
- Crushing injury of headS07
- Avulsion and traumatic amputation of part of headS08
- Other and unspecified injuries of headS09
- Superficial injury of neckS10
- Open wound of neckS11
- Fracture of cervical vertebra and other parts of neckS12
- Dislocation and sprain of joints and ligaments at neck levelS13
- Injury of nerves and spinal cord at neck levelS14
- Injury of blood vessels at neck levelS15
- Injury of muscle, fascia and tendon at neck levelS16
- Crushing injury of neckS17
- Other specified and unspecified injuries of neckS19
- Superficial injury of thoraxS20
- Open wound of thoraxS21
- Fracture of rib(s), sternum and thoracic spineS22
- Dislocation and sprain of joints and ligaments of thoraxS23
- Injury of nerves and spinal cord at thorax levelS24
- Injury of blood vessels of thoraxS25
- Injury of heartS26
- Injury of other and unspecified intrathoracic organsS27
- Crushing injury of thorax, and traumatic amputation of part of thoraxS28
- Other and unspecified injuries of thoraxS29
- Superficial injury of abdomen, lower back, pelvis and external genitalsS30
- Open wound of abdomen, lower back, pelvis and external genitalsS31
- Fracture of lumbar spine and pelvisS32
- Dislocation and sprain of joints and ligaments of lumbar spine and pelvisS33
- Injury of lumbar and sacral spinal cord and nerves at abdomen, lower back and pelvis levelS34
- Injury of blood vessels at abdomen, lower back and pelvis levelS35
- Injury of intra-abdominal organsS36
- Injury of urinary and pelvic organsS37
- Crushing injury and traumatic amputation of abdomen, lower back, pelvis and external genitalsS38
- Other and unspecified injuries of abdomen, lower back, pelvis and external genitalsS39
- Superficial injury of shoulder and upper armS40
130 more in this chapter.