I’m a U.S. citizen living with my mother in Russia. I’ve done some research and found that I am eligible for an SAT fee waiver, but I can’t find any information on where and how to get one as a citizen abroad.
The College Board website says, "Your school counselor or a representative of an authorized community-based organization will help you get a fee waiver." You should be able to get a fee waiver by speaking to the guidance counselor at your school (or, if you're homeschooled, a counselor at a high school in your area) and providing evidence of your eligibility. The College Board provides this guide to fee waivers that's directed towards counselors if your school counselor isn't familiar with the process. Your counselor can order fee waiver cards by calling +1 212-520-8600. Since the College Board distributes fee waiver cards to schools and qualifying agencies based on the number of fee waivers their students used during the previous year, you may need to get your counselor to order a card specifically for you. I assume there aren't many other high school students in your area who have been eligible for fee waivers in the past.