2024 marks the 50th anniversary of the establishment of National Institute on Aging (NIA) at NIH, which went on to become the largest and most important funder of aging research in the world. The articles in this collection are authored by recipients and leaders of major NIA initiatives to help commemorate this important occasion. Each of these contributions highlights the successes of these initiatives, while also looking forward at challenges that aging science and NIA are likely to face over the next 50 years.