Final Action Date vs Dates for Filing
The two charts
Every monthly Visa Bulletin has two charts for most categories: Final Action Dates and Dates for Filing. Final Action Dates show when a green card can be issued. Dates for Filing show when applicants may be allowed to submit paperwork earlier.
Which chart should I use?
If you are applying from inside the United States, USCIS announces each month whether adjustment-of-status applicants may use Dates for Filing or must use Final Action Dates. If USCIS allows Dates for Filing, you may be able to file I-485 even before the green card can be finally approved.
Check the Visa Bulletin first, then check the USCIS monthly filing chart page before making a filing decision.
Why it matters
Filing earlier can matter because a pending I-485 may open access to work authorization, advance parole, and portability options. The exact effect depends on your case, so treat the chart as a planning signal, not legal advice.