Authorities said the 49-year-old victim was attacked while she delivered mail to the home at 220th Place in Laurelton just before 1 p.m.
She was slashed in the left side of the face and taken to North Shore Manhasset Hospital in stable condition.
After attacking the worker, police say the 32-year-old suspect, Robert Powell, then retreated into his apartment and refused to come outside.
He was taken into custody about 90 minutes later.
He is charged with assault, obstruction of government administration and harassment.