06423 ZIP Code, East Haddam, CT
06423 is a ZIP code in East Haddam, Connecticut in Middlesex County. It covers 37 square miles of land. The closest ZIP codes are 06439, 06469 and 06412. 5,182 people live here in 2,137 households. With about 142 people per square mile it is lightly settled, and most homes are owner-occupied (96%). Median household income is $107,549, above the Connecticut median of $95,781; the median age is 51.7, older than most ZIP codes.
Quick facts
- Mailing city: East Haddam, CT
- County: Middlesex County
- Land area: 37 sq mi
- Population: 5,182
- Median household income: $107,549
- Carrier routes: 4 (2,066 homes)
Key figures
| Measure | Value |
|---|---|
| Residents | 5,182 |
| Households | 2,137 |
| Median household income | $107,549 |
| Income per person | $61,379 |
| Median age | 51.7 |
| Homeowners | 95.9% |
| Median home value | $373,700 |
| Median rent | $1,663 |
| Bachelor's degree or higher | 39.4% |
| Average commute (minutes) | 32.6 |
| Households with kids under 18 | 23.9% |
| Moved in the past year | 11.4% |
| Below the poverty line | 6.0% |
| Broadband internet | 90.0% |
| Speak a non-English language at home | 3.0% |
Household income
| % of households | Value |
|---|---|
| <$10K | 1.2% |
| $10–15K | 0.6% |
| $15–25K | 7.3% |
| $25–35K | 9.5% |
| $35–50K | 4.0% |
| $50–75K | 13.6% |
| $75–100K | 11.7% |
| $100–150K | 17.8% |
| $150–200K | 13.6% |
| $200K+ | 20.8% |
Age
| % of all residents | Value |
|---|---|
| <10 | 9.3% |
| 10–19 | 8.7% |
| 20–24 | 3.6% |
| 25–34 | 12.6% |
| 35–44 | 10.4% |
| 45–54 | 9.0% |
| 55–64 | 20.3% |
| 65–74 | 14.9% |
| 75+ | 11.2% |
Tenure
| % of housing units | Value |
|---|---|
| Owned, with mortgage | 45.7% |
| Owned outright | 38.3% |
| Rented | 3.6% |
| Vacant | 12.4% |
Type of building
| % of housing units | Value |
|---|---|
| Detached house | 93.5% |
| Townhome | 3.1% |
| 2–4 units | 3.4% |
| 5–19 units | 0.0% |
| 20+ units | 0.0% |
| Mobile / other | 0.0% |
Businesses in 06423
80 business establishments with 525 employees (ZIP Codes Business Patterns 2023).
- Construction: 14
- Other Services (except Public Administration): 12
- Professional, Scientific, and Technical Services: 8
- Administrative and Support and Waste Management and Remediation Services: 7
- Retail Trade: 6
- Health Care and Social Assistance: 6
- Accommodation and Food Services: 6
- Wholesale Trade: 4
EDDM carrier routes
06423 has 4 USPS carrier routes with 2,066 residential and 40 business mailboxes. Open the EDDM route map.
Carrier routes in 06423
06423 has 4 USPS carrier routes (4 rural (R)) with 2,066 residential and 40 business mailboxes. Routes range from 456 homes (R001) to 550 homes (R002); the median route has 530 homes. The Census counted 2,137 households in 06423 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.
| Homes per route | Routes |
|---|---|
| 1–249 | 0 |
| 250–499 | 1 |
| 500–749 | 3 |
| 750–999 | 0 |
| 1,000–1,499 | 0 |
| 1,500+ | 0 |
Best routes in 06423 for…
Most businesses
For B2B offers: office supplies, cleaning, IT, catering and commercial services.
- Route R004 — USPS business mailboxes 21, 523 homes
- Route R003 — USPS business mailboxes 12, 537 homes
- Route R001 — USPS business mailboxes 4, 456 homes
- Route R002 — USPS business mailboxes 3, 550 homes
Select these 4 routes on the route map
Every carrier route in 06423
| Route | Type | Homes | Businesses | Est. median income | Est. owners | Est. families with kids | Est. moved in past year |
|---|---|---|---|---|---|---|---|
| R001 | Rural | 456 | 4 | $149,242 | — | — | — |
| R002 | Rural | 550 | 3 | $108,386 | — | — | — |
| R003 | Rural | 537 | 12 | $108,386 | — | — | — |
| R004 | Rural | 523 | 21 | $108,386 | — | — | — |
Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 06423 on the EDDM route map.
How route demographics are estimated
Mailbox counts come from USPS; demographics are estimates
The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).
How a route gets its figures: the block-group length-share method
We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.
Margins of error
Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.
Different years
USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.
Why some routes show identical figures
Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.
Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.
Nearby ZIP codes
- 06439 (2.9 mi)
- 06469 — Moodus CDP, CT (4.6 mi)
- 06412 — Chester Center CDP, CT (5.9 mi)
- 06438 — Higganum CDP, CT (6.2 mi)
- 06415 — Colchester CDP, CT (6.8 mi)
- 06420 (7.2 mi)
- 06426 — Essex Village CDP, CT (7.3 mi)
- 06371 (7.4 mi)
Areas that include 06423
- East Haddam, CT ZIP codes — 1 ZIP code
- Middlesex County ZIP codes — 24 ZIP codes
- Connecticut ZIP code data
Where it ranks
- No. 2 of 21: highest share of owner-occupied homes in Middlesex County
- No. 5 of 21: highest share of residents who moved in during the past year in Middlesex County
- No. 7 of 21: highest median age in Middlesex County
Mail every home in 06423
Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.
EDDM guides
ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 06423, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.
Frequently asked questions
- What city is 06423 in?
- 06423 is a East Haddam, CT mailing address. None of its land lies inside a Census-defined city or community.
- What county is 06423 in?
- 06423 is in Middlesex County.
- What is the population of 06423?
- About 5,182 people (±494), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 4,821.
- What is the median household income in 06423?
- $107,549 (±$18,943), compared with $95,781 for Connecticut as a whole. Half the households in the ZIP code earn more and half earn less.
- How many carrier routes and mailboxes are in 06423?
- 4 USPS carrier routes with 2,066 residential and 40 business mailboxes (2,107 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
- What ZIP codes are near 06423?
- The closest, measured center to center: 06439 (2.9 mi), 06469 (4.6 mi, Moodus), 06412 (5.9 mi, Chester Center), 06438 (6.2 mi, Higganum), 06415 (6.8 mi, Colchester) and 06420 (7.2 mi).
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.