The below are eligible for a Sno-Isle Libraries card:
- Residents or property owners within the Sno-Isle Libraries District service area including:
- All unincorporated areas within Snohomish and Island Counties.
- All cities, towns, and rural partial-county library districts that have annexed to the Sno-Isle Library District.
- Tribal lands.
- Residents or property owners of jurisdictions within Washington State that provide equitable tax support for public library services.
- Organizations located within the Sno-Isle Libraries District service area.