Most times this is due to a user entry error ... however you can put in an accuracy claim if you believe the program was at fault ...
See this Any calculation errors on the part of TurboTax are covered under the Accurate Calculation Guarantee. TurboTax will pay any penalties and/or interest due to a calculation error but not any taxes owed. The Guarantee does not cover any user entry errors or omissions.
See this TurboTax support FAQ for the 100% Accurate Calculation Guarantee - https://ttlc.intuit.com/questions/2566201-what-is-the-turbotax-100-accurate-calculation-guarantee
TurboTax support FAQ for submitting a claim - https://ttlc.intuit.com/questions/1901269-how-do-i-submit-a-claim-under-the-turbotax-100-accurate-ca...
See this TurboTax support FAQ for documents needed to submit a claim - https://ttlc.intuit.com/questions/1901060-what-documents-do-i-need-to-submit-a-claim-under-the-turbo...
