Phelps also lost six months of funding from the sport's national governing body as a result of his second DUI arrest. The 29-year-old swimmer is banned from participating in USA Swimming-sanctioned meets through April 6, 2015.
USA Swimming said Phelps violated its Code of Conduct, and cited a section of its 2014 Rule Book in punishing him. Its executive committee approved the sanctions, which take effect immediately.
"Michael's conduct was serious and required significant consequences," said Chuck Wielgus, USA Swimming executive director. "We endorse and are here to fully support his personal development actions."
Phelps can still train with his North Baltimore club, but he had already qualified for the world championships in Russia next August, which is the biggest international meet leading up to the 2016 Rio de Janeiro Olympics.
Phelps came out of retirement earlier this year with his sights set on competing at a fifth Olympics in Rio. Being barred from the world meet could put a serious dent in those ambitions.
His latest arrest came about a month after Phelps won three golds and two silvers at the Pan Pacific Championships in Australia. He had retired after the 2012 London Olympics, having won a record 18 gold medals and 22 medals in four games.
Phelps's monthly funding stipend of $1,750 will be halted for six months, costing him a total of $10,500. That is small change compared to the millions he earns through several major endorsements, including Aqua Sphere, Subway, Under Armour, Omega and Master Spas.