Several years ago when I would organize for clients and need to dispose of medication or dispose my own medication I would drop off expired medication at CVS and they would dispose of it for me. Now that is not the case. You have to dispose of it using these prepaid TakeAway envelopes or boxes.
This website lets you put your zip code and see where there is place close to you to dispose of medication.
FDA suggests mixing expired medication with coffee grounds or kitty litter, putting in a container and throwing in the trash. DO NOT flush old medication as it can contaminate the environment.