Saving for your kids’ college tuition is tough. But what’s even tougher is deciding the most intelligent, tax-efficient order to tap those college savings: Should you start with 529 plans, cash or mutual funds?

With high school seniors soon heading off to college, parents are faced with the daunting task of figuring out the best way to tap the money they’ve saved for their kids’ higher education. After all, they want to ensure they can stretch those hard-earned dollars as far as they can.

What complicates matters when parents go to pay is not only the exorbitant cost — the average sticker price for tuition, fees, and room and board at a private college this past academic year was $48,170, according to The College Board — but the fact that the savings are spread around in a variety of accounts, ranging from cash to stocks and in investments that are shielded from taxes and those that are not.

“I always tell clients, it’s one thing to save for college,” says Marguerita Cheng, CEO of Blue Ocean Global Wealth based in Gaithersburg, Md. “Now, you have to learn how to pay for college.”

Others can have a negative impact on your financial aid package or reduce your eligibility for government tax credits, such as the American Opportunity Tax Credit, which maxes out at $2,500.

“You can always get a loan for college, but nobody is giving loans for retirement.