A new authentication process for IRS e-services is going to be put in place next month. Starting on October 24, if you plan to use any of the services and self-help tools on irs.gov, you will need to re-register using this new process. The purpose of this change is to help reduce fraud and ensure identity verification is more secure than before.
The process differs depending on whether you're a new e-services user or a returning user. New users will need to go through a more detailed process to verify their identity and finances. Returning users will have a slightly more expedited process. In either case, users will need to be able to provide their AGI during registration. For anybody having trouble registering or re-registering, the website will offer online assistance. To facilitate this, they will be hiring more staff to handle the volume of users requiring help with the new Secure Access.
Another important thing to note is the IRS will be phasing out the e-filing PIN this year. Those who have already secured a PIN will be able to use it for this tax year, but after that, the option will no longer be available.
For more information detailing these changes, check out this article from Accounting Today.