Skakel posted the bond immediately in Superior Court in Stamford, Conn., The (Stamford) Advocate reported. His lawyers had asked the court to set bail at $700,000.
Skakel, 53, was convicted of murder 27 years after the body of Martha Moxley was found in the upscale neighborhood where both families lived. At the time of the killing, both Skakel and Moxley were 15.
The court ordered Skakel to remain under GPS monitoring and to stay away from Moxley's relatives.
Skakel was the nephew of Ethel Kennedy and her husband, Sen. Robert F. Kennedy. His supporters included his cousin, Robert F. Kennedy Jr., who said Skakel helped him when both were struggling as adults with substance abuse problems.
"This is the first step in correcting a terrible wrong. We look forward to Michael being vindicated and justice finally being served," Skakel's family said in a statement after bail was set. "We are thankful to God that after 11 and one half years he will be reunited with his son. We are grateful for the love and prayers of Michael's many supporters who have sustained him through this ordeal."
A judge vacated Skakel's conviction and ordered a new trial last month, ruling that his lawyer at his 2002 trial had presented a woefully inadequate defense.