Users can expect to receive an email from Yahoo warning them of the impending change, which is expected to kick in June 30. Users who already have a Yahoo ID can sync their accounts or create a new set of Yahoo credentials.
"We want to make this transition as easy as possible," the Yahoo email said. "We appreciate your understanding during this transition."
Yahoo announced the decision first in March, she it said it was working on improving its use experience, which included changing its sign-in process for services like Flickr and Fantasy Sports.
"This new process, which now asks users to sign in with a Yahoo username, will allow us to offer the best personalized experience to everyone," a spokeswoman said at the time.
The Internet giant has been making a flurry of changes ever since CEO Marissa Mayer took over, which included revamping Flickr, launching a new version of its email software and cleaning its servers of unused accounts.