Possibly. However, if you do not receive a letter explaining the decrease in your refund then you will need to contact the IRS for any questions relating to your refund. Please see How do I contact the Internal Revenue Service (IRS)? for more information, including the IRS phone number and hours of operation. You may want to try calling right when they open since they have been very busy throughout the day.
In this public forum we cannot diagnose why your refund has been reduced. For additional information, please see this Help Article or this TurboTax blog.