If you receive a Direct PLUS Loan as a graduate or professional student, you don't have to make any payments while you're enrolled in school at least half-time, and for an additional six months after you graduate, leave school, or drop below half-time enrollment. 

If you are a parent borrower, you’ll generally be expected to start making payments on your Direct PLUS Loan once your loan is fully disbursed (paid out). However, you may request a deferment while your child is enrolled at least half-time and for an additional six months after your child graduates, leaves school, or drops below half-time enrollment. You don't have to make any payments while your loan is deferred. If the school your child is attending requires you to submit your request for a Direct PLUS Loan at StudentLoans.gov, you’ll have the option of requesting a deferment as part of the loan request process. You can also contact your servicer to request a deferment.

During any period when you're not required to make payments, interest will accrue on your loan. You may choose to pay the accrued interest or allow the interest to be capitalized (added to your loan principal balance) when you have to start making payments. Your loan servicer will notify you when your first payment is due. 

To apply for for a Federal Parent PLUS Direct Loan, you must complete the Master Promissory Note as well as the PLUS application to authorize a credit check. From the website, click “Sign In” under Manage My Direct Loans.