If you took advantage of the 2008 First-Time Homebuyer Credit (which was actually an interest-free loan), you'll repay it in equal portions for 15 years, starting with your 2010 tax return.
Your repayment is an additional tax that will either lower your refund or increase your tax bill through tax year 2025. If you got the full $7500 credit, the additional tax is $500 per year; otherwise, if you got less than that, your repayment is 6.66% of the total loan amount.
To get to this section in TurboTax, search for homebuyer credit in your TurboTax program and select the Jump to link in the search results.
Then, answer yes, enter the date your home was purchased, and follow the on-screen instructions. We'll calculate the tax and handle the rest.
Here's an IRS video about the First-Time Homebuyer Credit: