This is a poster presented at the 7th Shaw-IAU Workshop on Astronomy for Education, organised by the IAU Office of Astronomy for Education (OAE, https://astro4edu.org/shaw-iau/7th-shaw-iau-workshop/). Title: The Penn State Inservice Workshops in Astronomy (PSIWA) Presenter:William Niel Brandt (Pennsylvania State University) The PSIWA, now operating for 20+ years, are week-long summer workshops for Pennsylvania high-school physics and Earth/space science teachers aimed at helping them teach their students about galaxies, black holes, cosmology, stars, and other topics. They serve as a high-leverage method of improving understanding of astronomy; each of the attending teachers will teach hundreds of students. Teachers from diverse, under-served school districts are specifically recruited with scholarship funds. The PSIWA programs include lectures on subject material, discussions of pedagogical approaches, hands-on activities, nighttime observing, and guest presentations. I will describe the accomplishments of the PSIWA, their future prospects, and broader lessons learned. About the 7th Shaw-IAU Workshop:The 7th Shaw-IAU Workshop took place 18 - 21 November 2025. The Shaw-IAU workshops focus on astronomy education for primary and secondary school students and teacher training both in universities and in service. This year's Education focus session on Teaching with authentic data and the Science focus is on Galaxies.More details can be found on: https://astro4edu.org/shaw-iau/Keep up to date with future Shaw-IAU Workshops and other opportunities at the IAU Office of Astronomy for Education by joining our mailing list https://astro4edu.org/mailing-list/ Follow the IAU OAE on Bluesky and Facebook under @astro4edu