Despite the potential of PhET Interactive Simulations to foster engagement and participation in science education, they are currently inaccessible for many students with disabilities. This is due to the reliance on predominantly visual representations of concepts and interfaces that rely on dexterity with a mouse or touchscreen device. In 2014, the PhET project began an initiative to increase the accessibility of PhET's HTML5 simulations for students with and without disabilities, using inclusive design approaches. Since then, we have overcome technical challenges, started a (growing) accessible simulation design community, published the first keyboard and screen reader accessible PhET simulation, and engaged in research of inclusive features with students with diverse needs. Here, we share our progress, challenges, and the potential of creating accessible -and inclusive -educational resources for physics classrooms.