The IRS has changed the tax code to allow parents to switch the investments in their 529 plans twice this year, instead of just once.

That gives families whose college savings accounts haven't fully rebounded from the bear market another chance to move their money to better-performing mutual funds.

There are two basic types of 529 plans -- college savings plans, where you put money into investments like mutual funds to save for your child's future educational costs, and prepaid tuition plans, where your contributions are guaranteed to cover the cost for an in-state school. (Some plans also let you use the money for out-of-state or private schools.)

In the past, the plans, which are sponsored by educational institutions, state agencies and states, seemed like a can't-miss deal. Parents got to save money for their child's college expenses and get a tax break for doing it.

However, when the market crashed after the 2008 financial crisis, many 529 plans took a hit.

Assets in 529 college savings plans were down 21% in the fourth quarter of 2008 compared with the same quarter in 2007, according to Financial Research Corp. data released by the College Savings Foundation.

If your 529 account has lost a considerable amount of value, you might be tempted to just close it out.

Don't. You'll be taxed heavily for using money from it for anything other than educational expenses.

If your child is a year or two away from college and the account is low, remember that you won't be spending the entire amount in your 529 account during your child's freshman year.

Consider finding another way to pay for the first year of college and giving the account time to build back up. You can always use it to fund your child's sophomore, junior or senior year.

Click here to find out how to get a more accurate estimate of what you'll have to pay and why home equity lines of credit remain a good choice for paying college bills.