I have used the Walmart/Humana plan for the past 2 years. I pay $15/mo for the part D plan, have a $300 copay, but after I reach that, all but a couple of my Rxs are free. This plan uses RightsourceRX for the mail order. If I have an RX needed right away, I fill it at WMT however.

WMT is quite close to us, but I wasn't willing to forego the Part D and end up paying a penalty later on if I needed to sign up.

It comes down to what you are comfortable with, and what if ongoing medical problem and pre-existing conditions. Just remember, things can change in a heartbeat.

btw: What WMT offers isn't really a plan, it is simple inexpensive generic prescription drugs filled for 30 or 90 days.