Newmarket, NH ZIP code
The ZIP code for Newmarket, New Hampshire is 03857. It is in Rockingham County.
- Population in these ZIPs
- 9,463
- Avg. median income
- $100,800population-weighted
- Typical home value
- $562,700population-weighted
- Metro area
- Boston-Cambridge-Newton, MA-NH
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Newmarket, NH ZIP code list
| ZIP code | Population | Median income | Typical home value |
|---|---|---|---|
| 03857 | 9,463 | $100,845 | $562,700 |
Population and median household income: ACS 2020–2024 5-year estimates. Typical home value: Zillow Home Value Index (September 2026) where available, otherwise the ACS median owner-reported value. "PO Box" marks ZIP codes with no delivery area of their own. Methodology
Cities near Newmarket
Frequently asked questions
What is the ZIP code for Newmarket, NH?
The ZIP code for Newmarket, NH is 03857.
What county is Newmarket, New Hampshire in?
Newmarket ZIP codes are in Rockingham County.