If you need to make changes to your login credentials, you need to do so on the AAAS Identity Provider system. Log into myprofile.aaas.org. From there you can change your username/AAAS ID from the "Edit my Contact Information" tab. This will update your login for FellowsCentral, MemberCentral and Science Magazine. Your login information will be automatically updated in our database.
Note that the Science & Technology Policy Fellowships program maintains separate profile information on you, (aside from your username) please be sure to update your FellowsCentral profile with any changes to your contact information, employment, education, etc.