If you take medication for a chronic illness such as asthma, diabetes or heart disease, you can save a bundle using a mail-order drug program. Many insurance companies offer a 90-day supply for the cost of a single refill at a brick-and-mortar pharmacy. Just ask your healthcare provider to write scripts for an entire year, dispensing three months at a time. Delivery can take a week or more, so initiate refills well in advance of your last dose. And stick with your local pharmacy for short-term prescriptions.