What Apple services can I use with my AOL screen name?

The iTunes Store, App Store, and iBooks Store can be accessed using an AOL screen name. However, this is set to change starting on March 31, 2015. Apple is requiring all users to transition their AOL screen name to an Apple ID.

After the March 30 deadline, AOL Usernames that have not been converted to an Apple ID will permanently lose access to all Apple services and previous purchases.

Converting to an Apple ID will provide uninterrupted access to the iTunes Store, App Store, and iBooks Store. It will also add user access to iCloud and the Apple Online Store.