The creator of a program likened to a miniature MacArthur “genius” program for high school students will win the full adult prize today.

Deborah Bial, 42, of the Upper West Side, will be one of 24 honorees to receive the MacArthur Foundation’s $500,000 grants. Ms. Bial said the prize is especially flattering because the program that led her to win it, the New York City-based Posse Foundation, which she founded to help high school seniors graduate from college, mimics MacArthur’s values. “We want to recognize people for their potential,” she said. “That’s what Posse is about.”

Ms. Bial started the foundation just after graduating Brandeis University, when she was 23 and working in a New York City after school program.

A student sparked the idea. “I never would have dropped out of college if I had my posse with me,” he told her.

Her foundation now works to help students take “posses” with them, in the form of groups of nine peers the program selects. Scholarships provided by the foundation send each posse member to the same college. Support from the group, as well as from the foundation, which arranges scholarships to pay their way as well as regular meetings and career advice, helps them through the experience, Ms. Bial said.

More than 90% of participants have graduated, and all have attended prestigious universities. Bowdoin, Pomona, and Middlebury colleges, as well as Rice University and Ms. Bial’s alma mater, Brandeis, participate in the program. A 2006 report by the National Center for Education Statistics estimated that the national college graduation rate at 61% for private colleges and 36% for public.

Six cities now work with the Posse Foundation, and Ms. Bial said she hopes to expand that number to 10 by 2020.