Hey there, Helen.
Thanks for taking the time to join us here in the Community. I'd be happy to provide some information.
Since the Dental Benefit has specific codes that need to be applied to each employee separately, there isn't a way to enter a default code. I can see how having this option would be beneficial for you, so I recommend leaving feedback for our developers. Comments are viewed and considered as they create new features and updates for QuickBooks.
If you have any other questions, feel free to reach back out here.