How Do I Extend An Apple Warranty?
The standard Apple warranty for a Mac is one year of service with 90 days of phone support. You can purchase AppleCare any time during that first year to extend your warranty to a total of three years of service and phone support. You do not need to buy an AppleCare Protection Plan at the same time you buy a Mac and you don't even need to buy it from the same place (in fact, you can save a lot of money by not buying AppleCare from the Apple Store).
If you are interested in extending your warranty for free, you can use an American Express card when you buy your Mac. AMEX will add an additional one year warranty to the Mac, leaving you with a total of two years of service coverage. Filing a claim is as easy as calling the number on the back of your card.