Richest ZIP codes in St. Mary's County, MD
These are the 11 ZIP codes in St. Mary's County with the highest median household income, out of 11 with at least 1,000 residents. 20620 (Callaway, $165,972), 20636 (Hollywood, $163,690) and 20650 (Leonardtown, $143,116) lead the list. There is no single "best" ZIP code in St. Mary's County; the right one depends on who you want to reach, so the same ZIP codes are ranked several ways below.
Richest ZIP codes in St. Mary's County
| Rank | ZIP | Mailing city | Median household income | Residents | Households | Residential mailboxes |
|---|---|---|---|---|---|---|
| 1 | 20620 | Callaway | $165,972 ±$25,868 | 1,115 | 389 | 476 |
| 2 | 20636 | Hollywood | $163,690 ±$34,692 | 10,486 | 3,324 | 4,096 |
| 3 | 20650 | Leonardtown | $143,116 ±$22,483 | 16,094 | 5,642 | 5,712 |
| 4 | 20634 | Great Mills | $139,375 ±$17,358 | 7,088 | 2,694 | 2,820 |
| 5 | 20622 | Charlotte Hall | $124,063 ±$38,431 | 5,185 | 1,489 | 1,585 |
| 6 | 20690 | Tall Timbers | $122,750 ±$35,391 | 1,077 | 478 | 361 |
| 7 | 20659 | Mechanicsville | $121,654 ±$10,429 | 24,324 | 8,300 | 8,521 |
| 8 | 20619 | California | $119,432 ±$17,073 | 14,212 | 5,719 | 6,282 |
| 9 | 20618 | Bushwood | $105,508 ±$36,992 | 1,705 | 656 | 315 |
| 10 | 20653 | Lexington Park | $103,048 ±$7,210 | 26,852 | 11,028 | 10,223 |
| 11 | 20670 | Patuxent River | $70,371 ±$4,717 | 2,046 | 439 | 582 |
How we ranked them
Ranked by median household income (ACS 5-year estimates, 2020–2024). The Census Bureau caps published medians at $250,000; ZIP codes at the cap are shown as $250,000+ and ordered by population. ZIP codes need at least 1,000 residents to be ranked; 11 of 27 qualify.
Which of these to mail, and why
Higher-income ZIP codes suit offers with a bigger ticket: remodeling, pools, roofing, financial planning, private schools, premium dining. A median describes the middle household, not every door, so the routes inside each ZIP still vary.
The top five ZIP codes on this list hold 13,538 households, on 27 carrier routes with 14,689 residential mailboxes. Open any of them on the route map to see each carrier route's own figures before you choose.
Open 20620 on the EDDM route map
More rankings
- ZIP codes with the highest home values in St. Mary's County
- ZIP codes with the highest homeownership in St. Mary's County
- ZIP codes with the most families with kids in St. Mary's County
- ZIP codes with the most new movers in St. Mary's County
- Youngest ZIP codes in St. Mary's County
- Oldest ZIP codes in St. Mary's County
- Fastest-growing ZIP codes in St. Mary's County
- All St. Mary's County ZIP codes
Businesses that mail these ZIP codes
Map it and price it
EDDM guides
Frequently asked questions
- Which ZIP code in St. Mary's County has the highest median household income?
- 20620 (Callaway), at $165,972 (±$25,868), among 11 ZIP codes with at least 1,000 residents.
- How is this ranking calculated?
- Ranked by median household income (ACS 5-year estimates, 2020–2024). The Census Bureau caps published medians at $250,000; ZIP codes at the cap are shown as $250,000+ and ordered by population.
- 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.