PeopleImages | DigitalVision | Getty Images

This fall, tell your child to think twice before withdrawing from that class she hates. She could lose thousands of dollars in financial aid. That's because college students must meet a series of requirements, including maintaining a minimum C average and successfully completing a minimum number of credits, in order to qualify for the full amount of loans and grants they're expecting to receive. In the worst case, students who drop from full-time to less than half-time — that is, generally fewer than six credits per semester for undergraduates — may no longer be able to take out federal loans and may have to start repaying what they've already borrowed. "These days, almost every academic decision is a financial decision," said Sara Goldrick-Rab, professor of higher education policy and sociology at Temple University. "There is no such thing as 'Man, I really don't like that class.'" "They won't know what they're losing until they talk to their financial aid officer before making the decision," she said. Here's what you need to know if your child is thinking of going below full-time status.

Watch your credits

Ariel Skelley | DigitalVision | Getty Images

College students are required to meet certain standards in order to ensure their eligibility for financial aid. That's what's known in education parlance as "satisfactory academic progress." Though each school's policy on this may vary, students generally need to maintain a grade-point average of 2.0 or a C, and they must have successfully completed a specified number of credits by the end of each school year. "You need to take and pass enough classes to be consistent with graduation within 150 percent of the time frame — or six years for a bachelor's degree," said Mark Kantrowitz, publisher and vice president of research at Savingforcollege.com. "If you drop enough classes, you may lose eligibility entirely until you take and pass enough classes on your own dime," he said.

Financial aid eligibility

In order to receive federal student loans, you must be enrolled on at least a half-time basis. Part-time and full-time students are subject to the same loan limits: no more than $5,500 for dependent students in the first year of college.

These days, almost every academic decision is a financial decision. There is no such thing as 'Man, I really don't like that class.' Sara Goldrick-Rab professor of higher education policy and sociology at Temple University.

How much a student receives in Pell Grants, which are offered based on financial need and do not need to be repaid, will depend on enrollment status. The maximum Pell Grant for 2018-2019 is $6,095. Those who attend college part time will have their Pell Grant awards reduced accordingly: Half-time students are eligible for half of the award.

Paying up

If students fall below half-time status for more than one concurrent semester, their federal loans enter a six-month grace period and then repayment begins, said Megan Coval, vice president, public policy and federal relations at the National Association of Student Financial Aid Administrators. More from Personal Finance

Junior's not going to college? What you can do about your 529 plan

One in 8 divorces is caused by student loans

Teachers must budget for hundreds of dollars in school supplies Further, depending on the school and the circumstances behind the drop to part-time status, a college could require that a student repay aid already received, she said. Students should check these details with their financial aid office. Schools make a distinction between withdrawing from a class and dropping it, and this factors into whether a student is considered full time.

Add or drop

Sirinarth Mekvorawuth / EyeEm | EyeEm | Getty Images

If a student enrolls in a class and drops it prior to the school's "add-drop" deadline, bringing him below full-time status, the school may adjust his aid. However, if he remains in the course beyond the deadline and withdraws from it, he may still be considered full time and will be allowed to keep his financial aid package for that semester. "If you withdraw after that date, it shows that you've attempted the class, so you get to keep your enrollment status," said Coval. "You've attended the class for a greater portion of the semester." Students who are failing classes and stick around still run the risk of losing their aid: Remember that they have to successfully complete a number of classes to meet satisfactory academic progress standards "If a student is trying to drop a class that they are failing, keeping it may also hurt," said Goldrick-Rab. "You're damned if you do, and damned if you don't."

Stop before you drop