Lochte, whose 12 Olympic medals include six golds, was suspended after an escapade at the 2016 Rio de Janeiro Olympics.
The American veteran finished ahead of Britain's Xavier Mohammed (2:00.47), with Sam Stewart (2:01.51), to cap his return to USA Swimming-sanctioned competition in the wake of a 10-month ban.
Lochte, whose 12 Olympic medals include six golds, was suspended after an escapade at the 2016 Rio de Janeiro Olympics, in which he said that he and three teammates had been mugged after an all-night party.
Brazilian police later determined that the tale, which garnered international headlines and embarrassed the Games hosts, was largely fabricated.
Now the 33-year-old is hoping his comeback will carry him to the 2020 Tokyo Games -- although he was a bit further behind with his training than originally planned because of the demands of new fatherhood.
He and fiancee Kayla Rae Reid welcomed son Caiden in June.
"No matter what the time was tonight, I knew I could go faster," said Lochte, who owns the 200m medley world record of 1:54.00.
"I knew it wasn't going to be there with my lack of training this year. I put my family first and I have no regrets for that. Family is everything."