To be compliant with state law, centers are required to verify that you have your card on you with every purchase. It's for your protection, as well. Whether you're comfortable going to a center that doesn't require that is completely up to you.

If it's a few months before your due to renew, I'd suggest filling out a lost/stolen card form and they'll get a fresh one to you within a couple weeks.

http://www.cdphe.state.co.us/hs/medi...0MMR%20_2_.pdf