Thorpe, 61, who won on the PGA Tour three times in the mid-1980s and the Champions Tour more than 10 times as a senior golfer, pleaded guilty in September to two counts of failing to pay $1.6 million in income taxes on more than $5 million he earned from PGA events and endorsements from 2002 to 2004.
Thorpe ranked among the top 10 of the Champions Tour's career money list in 2004.
As part of his plea, Thorpe agreed to pay all taxes, interest and penalties owed to the U.S. Internal Revenue Service, which added up to more than $2 million, the Orlando (Fla.) Sentinel quoted federal prosecutors as saying.
Thorpe reported to the Federal Prison Camp in Montgomery, a minimum-security facility at Maxwell-Gunter Air Force Base.
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