Yates pleaded guilty in October to helping Worldcom overstate its earnings from 2000 to 2002 in a scandal that bankrupted the huge telecom company.
He told the judge he was instructed by his superiors to make adjustments to company books that had "no justification" and were designed to meet Wall Street expectations.
"There is not a day that goes by that I don't think back on my actions and regret my decisions," he said. "I chose the easy way out."
District judge Barbara S Jones also imposed a $5,000 fine and ordered Yates to report to Federal prison on October 10.
Worldcom, now known as MCI, was engaged in a $11 billion accounting fraud and in 2002 filed for Chapter 11 bankruptcy protection.
An MCI spokesman said the company has shed more than 15,000 employees over the past year.