I"ve lost my AARP membership card, how do I get one?

Do what you do to replace ANY lost card - call the issuer.
AARP's # is 1-888-OUR-AARP
Online directions for replacement


By Phone: 1-8OO-OUR-AARP
Open 7am-12 midnight.
go to AARP.com and request one.
I'd suggest you contact AARP and ask for a replacement. They will have a record of your membership, so the card isn't necessary to present to them. The card is needed only if you need to prove membership in AARP to a service provider (airline, etc.).

Here's what AARP says about lost cards:
Q: How do I replace my lost membership card?
A: Start with our Update Your Account area. You can request a replacement card once we've located your membership.

The first source will take you directly to the page in question. The second source is general AARP.