This may not apply to you, but I just found it out this past week, so thought I would pass it along. I went in on senior discount day, and the cashier asked if I qualified. I said no, that even my husband was only 52 (their age is 55). She asked if he has an AARP card, and said that Walgreens honors it, even though AARP starts at 50 and Walgreens at 55. She also said that you can go to your Walgreens online account and attach your AARP number directly to it, so I would get the additional discount automatically when I'm there on a senior discount day.
Terri