At CVS, I always scan my card 2-3 times at their coupon machine. I scan until it tells me it has no more coupons for me. I usually get 1-2 I can use that trip and the other 5-10 of them don't match up the sales I want to do then. I have been throwing them away, especially at the expiration date printed on them.
I had kept a scanner coupon that was $5 off $30 any baby purchase and it expired 10-10.
On 10-13, I was doing the the Huggies deal and saw I still had that baby coupon. I asked the cashier about it and she said it was store policy to honor expired CVS coupons, she thought the policy was for 2 weeks after the expiration but that she would always honor them up to a month past expiration.
The Huggies deal was already good and another $5 off made it great!
So, I will be holding on to these scanner coupons, just in case they will match up with a deal even after their expiration date.
I will add that the CVS I shop at is very customer and coupon friendly. I've heard that other stores are not so user friendly and that is a shame. So this may not work at every CVS but it wouldn't hurt to ask.