Priority Date

Your priority date is your spot in the visa line, usually the date USCIS received your petition. For categories with limited annual visas, like family preference and many employment categories, you wait until your priority date is current before the final step can finish. You compare your priority date against the monthly Visa Bulletin from the State Department. When the bulletin date passes yours, your number is available. This is why a petition can be approved while the green card itself waits. A current I-140 approval does not help if your priority date is years away.