In June 2021, PubMed began requiring users to link to a federated or third party account to be able to login to their own PubMed account, called a My NCBI account. The ability to create usernames and passwords has been disabled (as of June 22, 2021). 

Accounts may be created using one of the available 3rd party sign-in options. The only change is the login credentials; the account contents do not change. 

Examples of acceptable accounts that may be linked to My NCBI accounts are Google accounts, university accounts, login.gov, and eRA Commons.

To add a linked account to My NCBI, please see Important Changes to NCBI Accounts Logins