New open-stacks books are regularly featured on the "New Books" truck in the Reading Room.
Lists of new vault acquisitions are now posted to Folgerpedia once a year, in late summer (fiscal year runs from July 1 through June 30):
The Folger does not normally publicize acquisitions until the material has arrived and been processed. Exceptions include newsworthy public sales, such as the Robert S. Pirie sale, where lots for which the Folger was high bidder were announced through social media on the evening of the last day of the sale.
See also: Collection development policy