Exposure to ionizing radiation (W88) ICD-10-CM
The W88 code range covers exposure to ionizing radiation with 13 ICD-10-CM diagnosis codes. 9 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- exposure to sunlight X32
7th Character Note
Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.
- The appropriate 7th character is to be added to each code from category W88
7th Character
Indicates that a seventh character is to be assigned to codes in a subcategory.
- A - initial encounter
- D - subsequent encounter
- S - sequela
Codes in the W88 Range 13 codes · 9 billable
- W88 Exposure to ionizing radiationNon-billable
- W88.0 Exposure to X-raysNon-billable
- W88.0XXA Exposure to X-rays, initial encounter
- W88.0XXD Exposure to X-rays, subsequent encounter
- W88.0XXS Exposure to X-rays, sequela
- W88.1 Exposure to radioactive isotopesNon-billable
- W88.1XXA Exposure to radioactive isotopes, initial encounter
- W88.1XXD Exposure to radioactive isotopes, subsequent encounter
- W88.1XXS Exposure to radioactive isotopes, sequela
- W88.8 Exposure to other ionizing radiationNon-billable
- W88.8XXA Exposure to other ionizing radiation, initial encounter
- W88.8XXD Exposure to other ionizing radiation, subsequent encounter
- W88.8XXS Exposure to other ionizing radiation, sequela
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the W88 range.
Acute Radiation Syndrome
A condition caused by a brief whole body exposure to more than one sievert dose equivalent of radiation. Acute radiation syndrome is initially characterized by ANOREXIA; NAUSEA; VOMITING; but can progress to hematological, gastrointestinal, neurological, pulmonary, and other major organ dysfunction.
Radiation Pneumonitis
Inflammation of the lung due to harmful effects of ionizing or non-ionizing radiation.
Xerostomia
Decreased salivary flow.
About the W88 Code Range
The ICD-10 code section W88 covers medical coding for exposure to ionizing radiation, including types such as X-rays, radioactive isotopes, and other ionizing radiation. These codes specify the nature and timing of the exposure, such as initial encounters, subsequent encounters, or late effects (sequela).
This section helps medical coders accurately classify incidents where patients are exposed to ionizing radiation sources. For example, the ICD-10 code for exposure to X-rays (W88.0XXA) links to conditions commonly known as overexposure to medical diagnostic radiation or X-ray exposure accident. Similarly, W88.1XXA denotes exposure to radioactive isotopes, which may include overexposure to gamma rays or radiation from diagnostic isotopes, commonly described as radioactive isotope accidents. The category for other ionizing radiation, W88.8, covers a wide range of radiation sources including cosmic rays, industrial radiation, and radiation injuries from nuclear events, with synonyms referencing many specific radiation-induced conditions such as acute radiation syndrome and radiation pneumonitis. These distinctions enable precise documentation of radiation-related injuries or conditions for clinical, legal, and epidemiological uses.
Questions About This Page
How many billable codes are in the W88 range?
Of the 13 codes in this range, 9 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the W88 range classify?
The range classifies exposure to ionizing radiation. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
