The incident happened just before 5 p.m. Saturday.
Police say the victim had exited the elevator along with four other males and was walking towards his apartment when he was struck from behind with an unknown object and assaulted.
The suspects removed the victim's wallet, containing $150 cash, credit cards, his driver's license and his social security card.
The suspects then fled the location in an unknown direction.
The victim was taken to Kings County Hospital, where he remains in stable condition with a broken collar bone and head injuries.
The four suspects are described as black males in their late teens.
Police have released surveillance video of two persons of interest present at the scene, sought for questioning in regards to this incident. (CLICK HERE TO WATCH THE VIDEO)
Anyone with information in regards to this robbery is asked to call the NYPD's Crime Stoppers Hotline at 800-577-TIPS.