Skip to content

W89

Non-Billable (Header)

Exposure to man-made visible and ultraviolet light

Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)

What This Code Means

W89 is the ICD-10-CM diagnosis code for exposure to man-made visible and ultraviolet light. W89 sits in the ICD-10-CM chapter for external causes of morbidity (v00-y99), within the section covering exposure to electric current, radiation and extreme ambient air temperature and pressure (w85-w99).

Header codes like W89 cannot be reported on claims directly — they organize child codes that share clinical context but the actual diagnosis must be coded to the highest level of specificity supported by the documentation. Coders should look at W89's child codes and select the one that matches the patient's documented presentation, since payers reject header codes submitted as the primary diagnosis. For risk adjustment workflows, header codes never contribute to a Medicare Advantage member's RAF score on their own; only billable child codes that happen to map to a payment HCC affect risk-adjusted plan payments.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for W89 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Includes

  • exposure to welding light (arc)

Excludes 2 — Not included here, may code separately

  • exposure to sunlight (X32)

Child Codes

Code Hierarchy

W89Exposure to man-made visible and ultraviolet light
W89Exposure to man-made visible and ultraviolet light

Open W89 in the Interactive Encoder

See full code details, AI coding tips, HCC mappings, and related codes in our interactive encoder. Start your 14-day Pro trial — no credit card required.