You can request to have the 99 USD annual membership fee waived if you’re a nonprofit organization, accredited educational institution, or government entity based in the United States that will distribute only free apps on the App Store. Apple will review your request and contact you to let you know whether your request is approved.
Fee waivers are not available for:
● Organizations distributing paid apps or apps with in-app purchase on the App Store
● Members of the Apple Developer Enterprise Program
● Individuals and sole proprietors/single person businesses
More details at the link below!