ZIP code 21664
Where is ZIP code 21664?
Secretary, Maryland
Dorchester County · PO Box only ZIP code
ZIP code 21664 belongs to Secretary, Maryland in Dorchester County. 21664 is a PO Box only ZIP code: it is used for post office boxes at the Secretary post office, not for street addresses. It is in the Eastern Time zone and uses area codes 410, 443 and 667. About 635 people live in the 21664 area, where the median household income is $82,721. The closest ZIP codes are 21631 (East New Market, 1.3 mi southwest), 21835 (Linkwood, 4.8 mi south) and 21643 (Hurlock, 5.1 mi northeast).
| ZIP code | 21664 |
|---|---|
| Type | PO Box only (no street delivery) |
| Status | Active |
| City | Secretary |
| State | Maryland (MD) |
| County | Dorchester County |
| Time zone | Eastern Time · now |
| Area codes | 410, 443, 667 |
| Coordinates | 38.6093, -75.9474 map |
| 3-digit prefix | 216 |
Population and income in 21664
| Population | 635 · lower than 81% of Maryland ZIP codes |
|---|---|
| People per square mile | 2,182 · higher than 76% of Maryland ZIP codes |
| Median age | 34 years · lower than 91% of Maryland ZIP codes |
| Men / women | 47% / 53% |
| Median household income | $82,721 · lower than 75% of Maryland ZIP codes |
| Income per person | $29,251 |
| Below the poverty line | 5.5% |
| Bachelor’s degree or higher | 20% of adults 25+ |
| Median home value | $172,000 · lower than 95% of Maryland ZIP codes |
| Median rent | $1,175 a month |
| Housing units | 257 |
| Households | 217 (2.93 people on average) |
| Owners / renters | 70% / 30% |
| Land area | 0.29 sq mi (plus 0.02 sq mi of water) |
Source: U.S. Census Bureau, American Community Survey 5-year estimates (2020–2024) for ZIP Code Tabulation Area 21664. Census ZIP areas are close to, but not exactly the same as, USPS delivery areas.
ZIP codes near 21664
| ZIP code | City | Distance | Type |
|---|---|---|---|
| 21631 | East New Market, MD | 1.3 mi SW | Standard |
| 21835 | Linkwood, MD | 4.8 mi S | Standard |
| 21643 | Hurlock, MD | 5.1 mi NE | Standard |
| 21673 | Trappe, MD | 6.8 mi NW | Standard |
| 21613 | Cambridge, MD | 8.2 mi W | Standard |
| 21609 | Bethlehem, MD | 9.1 mi N | PO Box only |
| 21659 | Rhodesdale, MD | 9.3 mi E | Standard |
| 21655 | Preston, MD | 9.6 mi N | Standard |
| 21869 | Vienna, MD | 10 mi SE | Standard |
| 21632 | Federalsburg, MD | 11.8 mi NE | Standard |
| 21654 | Oxford, MD | 12.3 mi NW | Standard |
| 21861 | Sharptown, MD | 13.3 mi E | PO Box only |
Straight-line distance between ZIP code center points. Find every ZIP code within 10 miles of 21664 or measure the distance to another ZIP code.
How to address mail to 21664
PO BOX 123
SECRETARY MD 21664
Put the city, the two-letter state code and the ZIP code on the last line. Adding the 4-digit ZIP+4 code (21664-XXXX) helps mail sort faster but isn’t required.
Questions
- What city is ZIP code 21664?
- 21664 is a Secretary, Maryland ZIP code.
- What county is 21664 in?
- ZIP code 21664 is in Dorchester County, Maryland.
- What time zone is ZIP code 21664 in?
- 21664 is in the Eastern Time zone (America/New_York).
- What area code is 21664?
- Phone numbers in ZIP code 21664 use area codes 410, 443 and 667.
- What is the population of ZIP code 21664?
- About 635 people live in ZIP code 21664, according to the Census Bureau’s American Community Survey (2020–2024).
- What is the median income in 21664?
- The median household income in 21664 is $82,721 a year, lower than 75% of Maryland ZIP codes.
- Can I use 21664 for a street address?
- No. 21664 is only for PO Boxes. Street addresses in Secretary use another ZIP code.
- What ZIP codes are near 21664?
- The nearest ZIP codes to 21664 are 21631 (East New Market, 1.3 miles), 21835 (Linkwood, 4.8 miles), 21643 (Hurlock, 5.1 miles) and 21673 (Trappe, 6.8 miles).