Ok ... line 15 is just a total of lines 13 & 14 so look at your return and the IRS letter to see what else they changed so you know how or if you need to respond to the letter.
If you purchased Audit Defense for your tax
return, call Tax Resources, Inc. at (877)-829-9695, or report your notice on their web site at http://intuit.taxaudit.com/. Do not contact the
IRS. Let Tax Resources contact them for you.
This is the membership email you
should have gotten: https://ttlc.intuit.com/questions/1901569-when-will-i-get-my-audit-defense-membership-kit
Also read the
member agreement at this website -https://turbotax.intuit.com/corp/auditdefense.jsp
If you
did not purchase Audit Defense:
TurboTax has a special phone number for help with IRS
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/