Recently Social Security announced, that if you created a My Social Security Account before September 2021, you will need to update your account. Social Security states it is trying to provide its users with a simpler login experience and more secure online access.
Therefore, if you created a My Social Security account before September 18, 2021, you need to log in and link it to a Login.gov account to maintain access to your account. Once you log in using your old username and password, you will be prompted to set up a Login.gov account. You will then be able to access your My Social Security account through your Login.gov account.
Go to www.ssa.gov/myaccount to link your account or to confirm that it has already been linked.