With the fall semester starting soon, it’s time to finalize how you’re going to pay for college.

After scholarships and grants, the average cost for a semester is about $ 7,000 in public colleges and about $ 13,000 in private colleges.

More families use a mixture savings, income and loans to cover the rest of the cost.

Borrowing money should be the last resort. If you can’t cover the full cost up front, find out if the college offers a way to pay in installments.

But many families find they still need to borrow to fill the void. About 42% of them borrowed money to pay for their education last year, according to a survey published by lender Sallie Mae.

“There is still time to take out a loan, but you want to do it as soon as possible,” said Kalman Chany, author of Paying for College Without Going Broke, a book updated annually by The Princeton Review.

If you realize that the bill is higher than you expected, there are three borrowing options: federal loans that students borrow, federal loans that parents borrow, and loans from a private lender.

Use federal student loans first

the Federal direct loans for students come with low interest rates, flexible repayment options, and students are automatically eligible regardless of their income or credit history.

The interest rate is fixed and the same for each student. It is 4.45% for the 2017-2018 school year.

For some low-income students, there is another advantage. Their direct loans won’t start earning interest until six months after graduation. For everyone else, interest begins to accrue immediately.

But there is a limit to how much students can borrow. Direct loans are capped at $ 5,500 in your first year of college, $ 6,550 in your second year, and $ 7,500 in remaining years. (These loans also have a set-up fee of 1.1%, so you will receive almost $ 5,440 in your first year.)

To apply for the loan, first complete the Free Federal Student Aid Application (FAFSA), if it is not done yet. Then connect to StudentLoans.gov to accept the loan.

Related: Tuition-Free College Grows Up

Federal Parent PLUS Loans

For some, federal capped student loans may not be enough to cover the rest of the tuition fees. Parents may have to step in and borrow money from the federal program or from a private lender on their own.

Federal More ready Parents’ program should offer enough money to cover the rest of the tuition (including things like books and transportation) after using other financial aid.

But parents must pass a credit check to receive the Federal PLUS loan. They must not have “adverse credit history“which means they cannot be past due on other debts. In most cases, you can apply for the loan at StudentLoans.gov, but some colleges have a different process, Chany said.

Related: How the Average American Family Pays for College

The interest rate is fixed and the same for each borrower. This year, it’s 7%.

Parents are expected to start repaying PLUS loans immediately, unless they request a deferral while their child is still in school. They come with several refund options.

If a parent fails the credit check, there is good news. The student will automatically be able to borrow an additional $ 4,000 in direct loans.

But some parents with good credit might find a lower interest rate from a private lender.

What to look for in private student loans

Private student loans come from a variety of lenders including major banks, credit unions, a handful of states, and lenders who work specifically with students and their parents to pay for college education like Sallie Mae, CommonBond, and College Ave Student. Loans.

Conditions and prices can vary considerably. Some lend to parents and others to students, who will likely need a co-signing parent.

Related: Why Your Financial Aid Is Smaller Than You Expected

“Parents should be looking for more than the interest rate when it comes to private loans,” Chany said.

And borrowers are rarely entitled to the lowest rate advertised by a lender, he said.

Ask these questions before borrowing a private loan:

1. What is the interest rate and is it fixed or variable?
2. Are there any other fees? (PLUS loans have a 4.3% origination fee.)
3. When should you start repaying the loan?
4. Are flexible repayment plans available if you are experiencing financial difficulties?
5. Is the loan canceled in the event of death or disability?

Money from a private lender could take longer than the federal program. If you’re running out of time, be sure to call the college financial aid office two weeks in advance to make sure everything is in order. The school could prevent a student from signing up for classes or moving into the dormitory if the money isn’t there yet, Chany said.

CNNMoney (New York) First published on August 9, 2017: 12:54 p.m. ET