There isn't a module that is specifically designed to service an actual prepaid model but there might be some different ways to fulfill these functions using features native to the application, depending on your requirements. Are you working with employees, receivables, payables, sales, purchases, or something else entirely?

I work mostly with payables. I am trying to get payables scheduled so they can be automated over 12 months.

In payables, you would generally service your described requirement under a consignment or recurring bill model. Although consignment isn't supported natively, the Sage 500 AP module does have a Recurring Voucher feature. You should review online and form help for additional information.

Following is a user guide excerpt:

A recurring voucher is one generated for an ongoing, periodically recurring liability such as monthly rent. Use the Recurring Voucher feature to eliminate the need to re-enter the entire transaction every month.

In Maintain Recurring Vouchers, you define invoices for accounts payable items that occur on a regular basis. You then can select these invoices in Process Vouchers. In the batch entry window, Click Select Recurring to enter the selection criteria for recurring invoices. Once selected, you process the recurring voucher as you do regular vouchers.

Some of the features of this process are:

• Much of the information that you entered in Maintain Vendors automatically appears when you select the vendor in Maintain Recurring Vouchers.
• While entering a recurring voucher, the currency defaults from the vendor’s remit-to address. If necessary, you can override the currency.
• You can create a new voucher batch that consists only of recurring invoices, or you can add recurring invoices to an existing batch.
• You can select invoices based on processing cycle, a range of vendor classes, a range of vendor numbers, or a
  combination of factors.
• If you select the wrong recurring voucher, you can clear all recurring vouchers from the batch and reselect the correct recurring voucher. You cannot select a recurring voucher that exists in another pending voucher batch.
• You can make changes or adjustments to the voucher, just as you would a regular voucher. Once selected in a batch, these transactions become regular vouchers.