Driving through the Navajo Nation, you might spot one of Chip Thomas’s large-scale photo murals at an abandoned shopping center along the highway. When Thomas, 69, was still in the early stages of his work, a friend told him he should get a MacArthur grant, he recalled, though he brushed off the comment at the time. On Tuesday, he received one.

Thomas along with 19 others was a recipient of the annual “genius grants” presented by the John D. and Catherine T. MacArthur Foundation across the arts, sciences and humanities. The award comes with a no-strings-attached stipend of $800,000, disbursed over five years. Thomas, who is not Navajo but who worked as a physician there for 36 years, centered his photographic work on the Diné.

Because fellows neither apply for the honor nor receive any notification they are being considered, their selection comes as a complete surprise. Holly Jean Buck, an associate professor at the University at Buffalo, said she was under the impression that the foundation was calling to talk about climate change: “They kind of tricked me.” Felipe De Brigard, a professor at Duke University, said he ignored the first call, thinking it was spam.

Immanuel Wilkins, an alto jazz saxophonist at 29, is this year’s youngest recipient. Christine Sun Kim, an artist interested in the politics of sound, said she was looking forward to slowing down and being “a little bit more of a mom with more flexibility in her life.”