2020 ICD-10-CM Diagnosis Code T66

Radiation sickness, unspecified

    2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
  • T66 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.
  • The 2020 edition of ICD-10-CM T66 became effective on October 1, 2019.
  • This is the American ICD-10-CM version of T66 - other international versions of ICD-10 T66 may differ.
Type 1 Excludes
Type 1 Excludes Help
A type 1 excludes note is a pure excludes. It means "not coded here". A type 1 excludes note indicates that the code excluded should never be used at the same time as T66. A type 1 excludes note is for used for when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • specified adverse effects of radiation, such as:
  • burns (
    ICD-10-CM Diagnosis Code T20

    Burn and corrosion of head, face, and neck

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Type 2 Excludes
    • burn and corrosion of ear drum (T28.41, T28.91)
    • burn and corrosion of eye and adnexa (T26.-)
    • burn and corrosion of mouth and pharynx (T28.0)
    T20
    -
    ICD-10-CM Diagnosis Code T31

    Burns classified according to extent of body surface involved

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Note
    • This category is to be used as the primary code only when the site of the burn is unspecified. It should be used as a supplementary code with categories T20-T25 when the site is specified.
    T31
    )
  • leukemia (
    ICD-10-CM Diagnosis Code C91

    Lymphoid leukemia

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • personal history of leukemia (Z85.6)
    C91
    -
    ICD-10-CM Diagnosis Code C95

    Leukemia of unspecified cell type

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • personal history of leukemia (Z85.6)
    C95
    )
  • radiation gastroenteritis and colitis (
    ICD-10-CM Diagnosis Code K52.0

    Gastroenteritis and colitis due to radiation

      2016 2017 2018 2019 2020 Billable/Specific Code
    K52.0
    )
  • radiation pneumonitis (
    ICD-10-CM Diagnosis Code J70.0

    Acute pulmonary manifestations due to radiation

      2016 2017 2018 2019 2020 Billable/Specific Code
    Applicable To
    • Radiation pneumonitis
    Use Additional
    J70.0
    )
  • radiation related disorders of the skin and subcutaneous tissue (L55-L59
    ICD-10-CM Range L55-L59

    Radiation-related disorders of the skin and subcutaneous tissue

    • L55 Sunburn
    • L56 Other acute skin changes due to ultravio...
    • L57 Skin changes due to chronic exposure to ...
    • L58 Radiodermatitis
    • L59 Other disorders of skin and subcutaneous...
    )
  • sunburn (
    ICD-10-CM Diagnosis Code L55
    • L55 Sunburn
      • L55.0 Sunburn of first degree
      • L55.1 Sunburn of second degree
      • L55.2 Sunburn of third degree
      • L55.9 Sunburn, unspecified
    L55.-
    )
The following code(s) above T66 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to T66:
  • S00-T88
    2020 ICD-10-CM Range S00-T88

    Injury, poisoning and certain other consequences of external causes

    Note
    • 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
    Type 1 Excludes
    Use Additional
    • code to identify any retained foreign body, if applicable (Z18.-)
    Injury, poisoning and certain other consequences of external causes
Clinical Information
  • The effects of ionizing and nonionizing radiation upon living organisms, organs and tissues, and their constituents, and upon physiologic processes. It includes the effect of irradiation on food, drugs, and chemicals.
Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
Code annotations containing back-references to T66:
  • Type 2 Excludes: Z77.123
    ICD-10-CM Diagnosis Code Z77.123

    Contact with and (suspected) exposure to radon and other naturally occurring radiation

      2016 2017 2018 2019 - Revised Code 2020 Billable/Specific Code POA Exempt
    Type 2 Excludes
    • radiation exposure as the cause of a confirmed condition (W88-W90, X39.0-)
    • radiation sickness NOS (T66)

Diagnosis Index entries containing back-references to T66:

ICD-10-CM Codes Adjacent To T66
T65.92XD …… subsequent encounter
T65.92XS …… sequela
T65.93 Toxic effect of unspecified substance, assault
T65.93XA …… initial encounter
T65.93XD …… subsequent encounter
T65.93XS …… sequela
T65.94 Toxic effect of unspecified substance, undetermined
T65.94XA …… initial encounter
T65.94XD …… subsequent encounter
T65.94XS …… sequela
T66 Radiation sickness, unspecified
T66.XXXA Radiation sickness, unspecified, initial encounter
T66.XXXD Radiation sickness, unspecified, subsequent encounter
T66.XXXS Radiation sickness, unspecified, sequela
T67 Effects of heat and light
T67.0 Heatstroke and sunstroke
T67.01 Heatstroke and sunstroke
T67.01XA …… initial encounter
T67.01XD …… subsequent encounter
T67.01XS …… sequela
T67.02 Exertional heatstroke

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.