Fastest-growing ZIP codes in Washington County, MD
These are the 13 ZIP codes in Washington County with the fastest population growth, out of 13 with at least 1,000 residents. 21779 (Rohrersville, 27.0%), 21756 (Keedysville, 19.1%) and 21719 (Cascade, 17.6%) lead the list. There is no single "best" ZIP code in Washington County; the right one depends on who you want to reach, so the same ZIP codes are ranked several ways below.
Fastest-growing ZIP codes in Washington County
| Rank | ZIP | Mailing city | Population change | Residents | Households | Residential mailboxes |
|---|---|---|---|---|---|---|
| 1 | 21779 | Rohrersville | 27.0% | 1,311 | 462 | 420 |
| 2 | 21756 | Keedysville | 19.1% | 3,640 | 1,394 | 1,319 |
| 3 | 21719 | Cascade | 17.6% | 1,178 | 494 | 551 |
| 4 | 21722 | Clear Spring | 16.9% | 6,721 | 2,222 | 1,989 |
| 5 | 21783 | Smithsburg | 11.4% | 9,910 | 3,632 | 3,304 |
| 6 | 21795 | Williamsport | 10.9% | 10,144 | 3,935 | 4,115 |
| 7 | 21740 | Hagerstown | 4.9% | 64,792 | 25,276 | 26,763 |
| 8 | 21742 | Hagerstown | 1.8% | 34,069 | 13,231 | 14,437 |
| 9 | 21750 | Hancock | -7.5% | 3,417 | 1,628 | 1,686 |
| 10 | 21713 | Boonsboro | -8.2% | 9,846 | 3,899 | 3,877 |
| 11 | 21758 | Knoxville | -14.0% | 4,409 | 1,588 | 1,841 |
| 12 | 21782 | Sharpsburg | -17.6% | 3,704 | 1,522 | 1,426 |
| 13 | 21746 | Hagerstown | -21.5% | 2,361 | 0 | — |
How we ranked them
Ranked by the change in ACS population estimates between the 2015–2019 and 2020–2024 releases. Both are 5-year averages, and ZIP code areas were redrawn for 2020, so a large change can partly reflect a boundary change. Both periods must have at least 1,000 residents. ZIP codes need at least 1,000 residents to be ranked; 13 of 19 qualify.
Which of these to mail, and why
Growing ZIP codes add households every year, which means new homes, new routes and customers without a go-to provider yet. Check the route map: new subdivisions can appear as new carrier routes.
The top five ZIP codes on this list hold 8,204 households, on 16 carrier routes with 7,583 residential mailboxes. Open any of them on the route map to see each carrier route's own figures before you choose.
Open 21779 on the EDDM route map
More rankings
- Richest ZIP codes in Washington County
- ZIP codes with the highest home values in Washington County
- ZIP codes with the highest homeownership in Washington County
- ZIP codes with the most families with kids in Washington County
- ZIP codes with the most new movers in Washington County
- Youngest ZIP codes in Washington County
- Oldest ZIP codes in Washington County
- All Washington County ZIP codes
Businesses that mail these ZIP codes
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EDDM guides
Frequently asked questions
- Which ZIP code in Washington County has the fastest population growth?
- 21779 (Rohrersville), at 27.0%, among 13 ZIP codes with at least 1,000 residents.
- How is this ranking calculated?
- Ranked by the change in ACS population estimates between the 2015–2019 and 2020–2024 releases. Both are 5-year averages, and ZIP code areas were redrawn for 2020, so a large change can partly reflect a boundary change. Both periods must have at least 1,000 residents.
- Why are some ZIP codes missing?
- ZIP codes with fewer than 1,000 residents are left out because their survey estimates swing too much to rank, and so are ZIP codes where the Census Bureau did not publish this figure.
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.