Of course! The software just needs to know when the Principal payments will start back up again and it can calculate an accelerated payoff date based on when the actual principal payments start. Make sure to have enough discretionary income in the plan to account for when the higher payment of principal and interest starts or else the software will not be able to calculate your plan. For example, if your interest only payment is $1,100 and your discretionary income is $300 a month, your payment when the interest only period expires will not be able to exceed $1,400 ($1,100 + $300).