The U.S. Department of Education is now accepting applications for a third round of the Investing in Innovation contest.

Up for grabs is $150 million for school districts, groups of schools, and their nonprofit partners who have “innovative” ideas that are ready to be tried out on a larger scale. Applications for this competition, which got its start with the 2009 economic-stimulus package, are due May 29.

Just as in the previous two competitions, bigger grants are available for ideas that have more evidence of past success. The largest are “scale-up” grants of up to $25 million, while $15 million in “validation” grants will be available to those with moderate evidence. Find the “scale-up” application here and “validation” application here.

Smaller grants—up to $3 million—are set aside for “development” projects that are in the earliest stages. A pre-application for this category was announced last month.