The 22-time Olympic medalist will compete for the first time since the 2012 London Games at a meet in Mesa, Ariz., on April 24-26.
Bob Bowman, the swimmer's longtime coach, told The Associated Press on Monday that Phelps is entered in three events — the 50- and 100-meter freestyles and the 100 butterfly.
"I think he's just going to test the waters a little bit and see how it goes," Bowman said by phone from Baltimore. "I wouldn't say it's a full-fledged comeback."
Phelps returned to training last fall and re-entered the U.S. drug-testing program. He has completed his six-month waiting period by the U.S. Anti-Doping Agency to be eligible for competition.
Bowman said Phelps is "pretty far" from being back in top form. He's been training Monday through Friday with Bowman's team at the North Baltimore Aquatic Club in his hometown.
"He's gotten back into good shape since September," the coach said. "He can give a good effort and certainly not be embarrassed. He's in enough shape to swim competitively."
Besides Phelps, USA Swimming said Olympians Ryan Lochte and Katie Ledecky are among those expected to swim in the Arena Grand Prix at Skyline Aquatic Center.
"I'm excited to see what he can do," Ledecky told the AP by phone in between classes at her high school in Maryland. "Definitely, it'll bring some more energy to swimming again."
Phelps turns 29 in June and is the winningest and most decorated athlete in Olympic history. He captured 18 gold medals and 22 medals overall at the last three Summer Games. He broke Mark Spitz's record for a single Olympics by winning eight gold medals at Beijing in 2008.
If he comes back and doesn't dominate, Bowman said it wouldn't tarnish Phelps' reputation. "His legacy is sealed," the coach said. Ledecky agreed that Phelps has nothing to lose by diving back in.
"It's just for his own personal kind of thing," she said. "He's already done so much. Whether he adds a couple more gold medals or not, what he's done has been so incredible, whatever he does next should be accepted by all."
Phelps had vowed that he wouldn't swim into his 30s. Since retiring less than two years ago, he has stayed busy with a chain of swim schools, a foundation focused on water safety and appearances on behalf of his sponsors. He devoted lots of time to golf and participated in a reality show with famed coach Hank Haney.
