Gulp. The bills that parents are receiving now for fall's college costs are among the most horrifying many will ever receive.

The shock doesn't simply come from the number, perhaps $15,000 or more. It's from the timing. Often, you have to come up with the money in about four weeks, or the student won't be allowed to sign up for classes.

So get ready to borrow, and try to do it as painlessly as possible. Remember, if you were trying to pay for your home in just four weeks, that bill would be horrifying, too. But you break mortgage payments into monthly bites, so the cost is bearable.

You do that with college student loans, paying over 10 years. Take some time with loan options because they differ significantly.

Things used to be simpler. Federal student loans tended to be the lowest-cost, an easy choice. In the early 2000s, students could lock in interest rates below 3 percent.

But Congress changed that, and students face relatively high interest on some federal loans, even though other loans are at all-time lows.

For example, 30-year home mortgages have interest rates below 4 percent, so the 6.8 percent on some federal Stafford loans is hard to stomach. Federal PLUS loans for parents are at 7.9 percent.

It might be tempting to turn away from federal loans and choose private loans instead.

How to decide? If your income is low enough to qualify for what's called a subsidized Stafford loan, that's a good deal. A loan your child takes out carries just a 3.4 percent interest rate. Feel free to borrow the $3,500 maximum for freshmen if you qualify. See rules at

When they finish college, graduates have 10 years to pay off the federal loans; many get extended plans.

If your child needs additional money for college, turn next to federal Perkins loans. These generally are reserved for lower-income students, but if your family is middle-income and your child is attending a high-priced school attended by affluent students, he or she might qualify. The interest rate is 5 percent.

After that comes another type of federal loan, known as an unsubsidized Stafford loan. It's not as attractive as Perkins or subsidized Stafford loans because you have to pay the aforementioned 6.8 percent interest.

So rather than an unsubsidized Stafford loan, you might be attracted to non-federal loans. Some private loans, offered by banks and other lenders, offer lower rates than you will see on unsubsidized Stafford loans. But beware. You have to check out the details.

Federal loans, fixed rates. They are 6.8 percent now and will stay that way during the full 10 years your child pays back the loans. Try this calculator to see payments:

Fees on federal Stafford loans are 1 percent; private loans can be much higher.

Private loans typically offer variable rates. So maybe you start with an enticing interest rate below 6.8 percent, but in the years ahead, it jumps.

Make sure you know exactly how high it can go. The last thing you want is an interest rate of 10 percent or higher. And if you imagine the interest rate going down, think again. Interest rates are near all-time lows now.

Some private loans are fixed, so the rate won't go up. But some also might require you to start making payments while a student is still in college, a burden most families can't handle. In addition, parents usually must co-sign; if the graduate misses payments, the parents must pay.

Federal loans give students some advantages that private loans typically do not. If you take a position that serves society, say with Head Start or the Peace Corps, you could receive forgiveness on your loans. Also, if you have trouble paying federal loans because your income is too low, the federal government gives you a break on payments.

Your college financial-aid office should help you through the decisions, and you can apply for loans there.

Gail MarksJarvis is a personal-finance columnist at the Chicago Tribune. Contact her at