ZIP Codes in Haddam, CT
Haddam uses 1 ZIP code, all in Lower Connecticut River Valley County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 1 Haddam ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 06438 | standard | Lower Connecticut River Valley | 2,887 |
Finding a ZIP+4 in Haddam
Knowing which of these 1 ZIP codes covers an address only gets you partway. The four-digit extension identifies the specific delivery point — typically one side of one block. Two houses facing each other on the same Haddam street almost always have different ZIP+4 codes even though they share all five leading digits.
Appending ZIP+4 to a mailing list?
Upload a CSV of Haddam addresses and download it complete.