Conrad Kennebrew, of Garland Lane, whose 28th birthday is Thursday, was charged with third-degree robbery of the TD Bank at 474 Portion Rd.
Kennebrew was ordered held on $50,000 bond or $25,000 cash bail after his arraignment Wednesday at First District Court, Central Islip.
Police said Kennebrew entered the bank on June 8, handed a teller a plastic bag and announced a robbery.
He left with an unspecified amount of money from the teller's drawer, police said.
In a Wednesday news release, police did not say what led them to Kennebrew.