The founder of the Florida Tea Party has arrived at the United State penitentiary in Atlanta to begin serving his 15-month sentence for income tax crimes, according to the Bureau of Prisons.

Doug Guetzloe, 58, was convicted in February of two federal crimes for not filing tax returns for 2005 and 2006. He received a total of $374,000 in income over those two years, according to testimony at his federal trial. He was sentenced May but was allowed to delay his arrival at the penitentiary until Monday so he could resolve some medical issues.

The government also noted Guetzloe filed delinquent tax returns from 1992 through 2004 and, as a result, was forced to pay more than $310,000 in back taxes, interest and penalties.

Guetzloe, founder of a group called Ax the Tax, was also a political consultant who a grand jury found was paid more than $100,000 in “hush money” by the Orlando Orange County Expressway Authority, payments arranged by the board chairman who said he hoped it would mute Guetzloe’s criticism of a toll increase.

Guetzloe has also been convicted of a state election crime and completed a 60-day sentence for that crime in 2011.