"I'm both thrilled and terrified, my usual feelings at this point. I'll be hiding out this summer revising, my favorite part of the process," Blume, 76, said in a statement.
The as-yet-untitled novel will be the iconic author's first for adults since 1998's Summer Sisters, the story of two friends who spend their summers together.
Blume's Knopf editor Carole Baron told the New York Times that the book is "quintessential Judy."
"It's pure Judy Blume, writing about family and about friendships, about love, about betrayal. It's quintessential Judy," she said.
It's official! Best part of writing this summer. Can't wait to get to NM Judy Blume Novel for Adults Set for 2015 http://t.co/2Htam5IQHn— Judy Blume (@judyblume) June 25, 2014