LA QUINTA, Calif. -- Phil Mickelson said he will make "drastic changes" because of federal and California state tax increases.

"It's been an interesting offseason," Mickelson said Sunday after the final round of the Humana Challenge. "And I'm going to have to make some drastic changes. I'm not going to jump the gun and do it right away, but I will be making some drastic changes."

The 42-year-old golfer said he would talk in more detail about his plans -- possibly moving away from California or even retiring from golf -- before his hometown Farmers Insurance Open, the San Diego-area event that starts Thursday at Torrey Pines.

"I'm not sure what exactly, you know, I'm going to do yet," Mickelson said. "I'll probably talk about it more in depth next week. I'm not going to jump the gun, but there are going to be some. There are going to be some drastic changes for me because I happen to be in that zone that has been targeted both federally and by the state and, you know, it doesn't work for me right now. So I'm going to have to make some changes."

In November, California voters approved Proposition 30, the first statewide tax increase since 2004. It boosted the state tax rate on incomes of more than $1 million from 10.3 percent to 13.3 percent.

The federal taxes for Mickelson's tax bracket will also increase in 2013. According to the Wall Street Journal, rates on single incomes of more than $400,000 will go from 35 percent to 39.6 percent, while the Social Security tax will be raised from 4.2 percent to 6.2 percent.

"If you add up all the federal and you look at the disability and the unemployment and the Social Security and the state, my tax rate's 62, 63 percent," said Mickelson, who lives in Rancho Santa Fe. "So I've got to make some decisions on what I'm going to do."

Last year, Mickelson flirted with becoming a part-owner of the San Diego Padres franchise, which sold for $800 million in August. He was asked Sunday whether there was a correlation between the tax increases and what happened to the Padres' deal.

"Absolutely," Mickelson said.

He later explained why he was waiting to provide more details.

"I'll probably be in the media center, and I'll probably be a little more open to it because San Diego is where a lot more things, it's where I live, it's where the Padre thing was a possibility, and it's where my family is," Mickelson said. "And it just seems like a better fit than right here off of 18 on Palm Springs."

Mickelson closed with a 66 on Sunday to tie for 37th at 17 under in his season debut.

"I was rusty starting the year," Mickelson said. "I had a great four days here where I can work on my game with perfect weather and wonderful golf courses, where I could build some momentum. Heading into San Diego, I feel a lot more confident."

The tournament was his first since the HSBC Champions in early November in China. The Hall of Famer has 40 PGA Tour victories.

Information from The Associated Press was used in this report.