Put a pile of money on the table before thousands of retirees from two major carmakers. Will they grab it or skip it and stick with a regular monthly check?

A group of white-collar General Motors retirees have until July 20 to decide if they want a payout of $300,000 or $500,000 or so. Some even are staring at $1 million. Some experts say offers to blue-collar retirees could be next.

The trade-off is that if they take the lump sum, they'll give up a steady, monthly check. “The downside is you can run out of money,” says Marilyn Capelli Dimitroff, president of Capelli Financial Services.

A lump sum might offer some individuals more flexibility — and certainly being able to roll over $300,000 or more into your own IRA sounds attractive. But it's not something for everyone — and the uproar among auto salaried retirees from the two carmakers shows that people aren't exactly comfortable with a choice.

GM and Ford Motor want to unload billions of dollars in pension obligations — and the automakers are presenting pension buyouts or changes to about 216,000 retirees, surviving spouses and some former white-collar employees