Blue Cross and Blue Shield Association provider directories?

For the BlueCard (national) program, you may search for doctors or hospitals under the "Find a Doctor or Hospital" link of bcbs.com (the association website).

To search locally, it is best to use your local individual plan's website, which will also have a link to their provider directory. For instance, in Arizona, you would go to azblue.com, click on the "Members" tab, then in the "Just for Members > Select a Member Resource" dropdown in the right column, you would select "Find a doctor or hospital." To my knowledge, though individual websites are laid out differently of course, all the Blue plans have a similar thing.