did you report the sale? did you specify that you lived in and owned it for any 2 out of 5 years before the date of sale? was the gain more than $250,000 if single or $500,000 if married (assuming your spouse live in it for 2 years before sale). the excess would be taxable. was there a previous sale of a principal residence within 2 years that you excluded the gain? the exemption would be less.
we can see your return or notice or closing documents so
The Audit Defense service is provided by TaxResources, Inc., also called TaxAudit.com, in partnership with TurboTax. If you paid for Audit Defense and you received an IRS notice, call TaxResources, Inc. at 877-829-9695, or report your IRS notice on their web site at http://intuit.taxaudit.com/. Do not contact the IRS until you have spoken to TaxResources. They may contact the IRS on your behalf.
if you didn't purchase audit defense you can try Audit Support
TurboTax has a special phone number for help with IRS/state tax letters, which will be easier than going through regular Customer Support. At the page below, click on the blue button that says "Get Help from TurboTax Support". Then it will ask you what tax year is your letter. Then it will ask you what the letter concerns. Then it will show you the phone number during posted business hours.
https://support.turbotax.intuit.com/irs-notice/audit-support/
