Substantially Equal Periodic Payments (SEPP) is a method that allows you to withdraw funds from your retirement account before you reach 59 ½ years old without incurring a 10% early withdrawal penalty. There are three IRS-approved methods for calculating SEPP distributions, including the Required Minimum Distribution (RMD) method, the Fixed Amortization method, and the Fixed Annuitization method. However, once a SEPP program starts, it must continue for five years or until the account holder turns 59 ½, whichever is longer.