Hi Kathie-

YES!  You can pay for your Walt Disney World vacation package in installments.  If you are booking a package, your initial deposit of $200 (it may be more if you've booked airline tickets or added vacation insurance) will be due within 7 days of booking your vacation, then the BALANCE of your package is due 45 days prior to check in.  Once you book, you'll receive an invoice in the mail for your vacation, and installment payment information is included on the back of your that invoice under the "Deposit and Payment Procedures" heading (they also include an address to mail check payments). 

You can also manage your payments online at www.disneyworld.com and clicking on the "My Vacation" link.

Have a magical vacation!
Amanda