Oldest ZIP codes in Grant County, WA
These are the 11 ZIP codes in Grant County with the highest median age, out of 11 with at least 1,000 residents. 99115 (Coulee City, 50.5), 99133 (Grand Coulee, 49.4) and 98857 (Warden, 36.4) lead the list. There is no single "best" ZIP code in Grant County; the right one depends on who you want to reach, so the same ZIP codes are ranked several ways below.
Oldest ZIP codes in Grant County
| Rank | ZIP | Mailing city | Median age | Residents | Households | Residential mailboxes |
|---|---|---|---|---|---|---|
| 1 | 99115 | Coulee City | 50.5 ±9.2 | 1,369 | 552 | — |
| 2 | 99133 | Grand Coulee | 49.4 ±6.4 | 1,115 | 536 | — |
| 3 | 98857 | Warden | 36.4 ±4.5 | 4,062 | 1,315 | 750 |
| 4 | 98851 | Soap Lake | 35.9 ±6.2 | 4,437 | 1,604 | 987 |
| 5 | 98837 | Moses Lake | 34.4 ±1.1 | 49,455 | 18,264 | 19,148 |
| 6 | 98848 | Quincy | 33.5 ±2.2 | 12,854 | 4,024 | 4,991 |
| 7 | 98823 | Ephrata | 32.0 ±3.6 | 12,188 | 4,379 | 4,966 |
| 8 | 99357 | Royal City | 31.4 ±2.6 | 3,843 | 996 | — |
| 9 | 99349 | Mattawa | 29.4 ±1.3 | 8,143 | 2,388 | — |
| 10 | 99344 | Othello | 26.8 ±1.5 | 19,534 | 5,422 | 6,024 |
| 11 | 99321 | Beverly | 22.5 ±5.0 | 1,047 | 173 | — |
How we ranked them
Ranked by median age of all residents, highest first (ACS 5-year estimates, 2020–2024). ZIP codes need at least 1,000 residents to be ranked; 11 of 18 qualify.
Which of these to mail, and why
Older ZIP codes respond to health care, hearing and vision, Medicare plans, home safety, estate planning and services that come to the door.
The top five ZIP codes on this list hold 22,271 households. Open any of them on the route map to see each carrier route's own figures before you choose.
Open 99115 on the EDDM route map
More rankings
- Richest ZIP codes in Grant County
- ZIP codes with the highest home values in Grant County
- ZIP codes with the highest homeownership in Grant County
- ZIP codes with the most families with kids in Grant County
- ZIP codes with the most new movers in Grant County
- Youngest ZIP codes in Grant County
- Fastest-growing ZIP codes in Grant County
- All Grant County ZIP codes
Businesses that mail these ZIP codes
Map it and price it
EDDM guides
Frequently asked questions
- Which ZIP code in Grant County has the highest median age?
- 99115 (Coulee City), at 50.5 (±9.2), among 11 ZIP codes with at least 1,000 residents.
- How is this ranking calculated?
- Ranked by median age of all residents, highest first (ACS 5-year estimates, 2020–2024).
- 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.