Can I Gate Check instead of Ticket Counter?
 

I connect to DIA from another airline. I have already paid Frontier to check a bag, but didn't want to depart security to do it at the ticket counter. Can I bring my bag to the gate and check it there, as I have already paid the checked bag fee? Or do I need to exit security and do it there?

The answer is probably yes but I doubt they have a policy published anywhere. I'm curious what circumstances are leading to this situation? Are you carrying it on when flying the other airline?

Plan to exit security to check your bag or to pay for a carry-on bag. Security lines in Denver can be no joke -- very long and time consuming without Clear or at least Precheck.