In simple words: This code represents a general diagnosis of radiation sickness when the specific effects are not known or not documented.

Radiation sickness, unspecified. Excludes1: 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.-)

Example 1: A patient presents with nausea, vomiting, and fatigue after an accidental exposure to an unknown radioactive source. The specific effects of the radiation are not yet determined. T66 is used until a more specific diagnosis can be made., A worker at a nuclear power plant experiences a radiation leak but shows no immediate symptoms. The code T66 is assigned for monitoring, as they are at risk for unspecified long term radiation effects. , A patient undergoing radiation therapy for cancer experiences generalized weakness and malaise, but no other specific symptoms. The code T66 can be used if the symptoms are attributable to radiation exposure but don’t meet the criteria for a more specific diagnosis.

Documentation should include details of the radiation exposure (type, source, dose if known), the onset and nature of symptoms, and any relevant medical history.

** This is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. As of November 30, 2024, this code is active.Refer to iFrameAI product for further details and to validate this information against the most current data.