Which ZIP code in St. Mary's County has the highest median age?

20618 (Bushwood), at 52.0 (±4.9), among 11 ZIP codes with 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.

Oldest ZIP codes in St. Mary's County, MD

These are the 11 ZIP codes in St. Mary's County with the highest median age, out of 11 with at least 1,000 residents. 20618 (Bushwood, 52.0), 20622 (Charlotte Hall, 49.4) and 20690 (Tall Timbers, 45.7) 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.

Oldest ZIP codes in St. Mary's County

Rank	ZIP	Mailing city	Median age	Residents	Households	Residential mailboxes
1	20618	Bushwood	52.0 ±4.9	1,705	656	315
2	20622	Charlotte Hall	49.4 ±7.0	5,185	1,489	1,585
3	20690	Tall Timbers	45.7 ±17.8	1,077	478	361
4	20620	Callaway	41.6 ±7.9	1,115	389	476
5	20636	Hollywood	39.4 ±4.3	10,486	3,324	4,096
6	20650	Leonardtown	38.6 ±1.4	16,094	5,642	5,712
7	20659	Mechanicsville	37.5 ±1.7	24,324	8,300	8,521
8	20619	California	36.6 ±2.5	14,212	5,719	6,282
9	20653	Lexington Park	34.8 ±1.5	26,852	11,028	10,223
10	20634	Great Mills	32.0 ±4.0	7,088	2,694	2,820
11	20670	Patuxent River	22.9 ±1.5	2,046	439	582

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 27 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 6,336 households, on 13 carrier routes with 6,833 residential mailboxes. Open any of them on the route map to see each carrier route's own figures before you choose.

Open 20618 on the EDDM route map

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Businesses that mail these ZIP codes

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Frequently asked questions

Which ZIP code in St. Mary's County has the highest median age?: 20618 (Bushwood), at 52.0 (±4.9), 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.