Department of State website:

Current Visa Bulletin  (Employment- and Family-Based)

Whether to refer to “Dates for filing” or “Final action dates”  (USCIS website)

Employment-based quota movement:

China (PRC)  |  India  |  Mexico  |  Philippines  |  All other countries

Family-based quota movement:

China (PRC)  |  India  |  Mexico  |  Philippines  |  All other countries

Visa retrogression:

Visa Retrogression FAQ (E0531)

The Visa Bulletin has two charts each for family and employment-based immigration: “Application Final Action Dates” (in which the Final Action Date is one’s Priority Date) and “Dates for Filing Applications”. Each month, USCIS posts on their website which chart can be used, https://www.uscis.gov/visabulletininfo. If USCIS posts that the Dates for Filing Visa Applications chart can be used in a given month, this means USCIS can accept applications for adjustment of status, and provide the ancillary benefits that flow from adjustment of status, even before the priority date is current.  However, if USCIS posts that the Application Final Action Dates chart must be used, then applicants must wait until their traditional priority date is current to apply for adjustment of status or consular visa application.  For more information, see https://www.jackson-hertogs.com/october-visa-bulletin-new-procedures-for-accepting-cases/.