Roger Lee Hayden, brother of 2006 world champion Nicky, will race in Moto2 at Indianapolis in a team fronted by Kevin Schwantz.
Erion Racing will run an American Honda entry for the 27-year-old former AMA Supersport champion, who will ride a Moriwaki chassis.
"This is a great opportunity for me to race in front of my home crowd at a MotoGP event," said Hayden.
"The Moto2 class is really competitive and I'm looking forward to jumping in the middle of it."
Nicky Hayden welcomed his brother's opportunity, but hoped he would get enough preparation to do himself justice.
"It's a huge opportunity for him. I know they're working on getting the bike and hopefully it will come together in time to do it right," said the elder Hayden.
"To just ride the bike one time then show up in that field would be a bad deal with how tough the competition is. Hopefully we can get some time on the bike and show what he can do."