Originally Posted by
PowerLu
In addition, if you have a paid first class ticket (not upgrade) and are flying Alaska metal, even on domestic flights, you can also get into Alaska lounges without any membership. Just show your boarding pass that says First Class (and not "U" fare).
This is no longer true for most flights. Only flights 2100 miles or longer in paid First are eligible.
As others have said, your membership gets you access, as long as you have the physical card with you. And you must be flying on either AA or AS.