I’m looking for a list of ZIP codes that also includes ZIP codes that enclose other ZIP codes. That is, some ZIP codes are post office boxes, and have no physical area, except the PO box. But the PO box is physically located inside or enclosed by another ZIP code. Another example is buildings, perhaps from one company. Anyone know where I can find such a list?
Gene Shackman, Ph.D.
Public Health Information Group
NYS Department of Health