Which ZIP code in St. Mary's County has the fastest population growth?

20670 (Patuxent River), at 42.0%, among 9 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.

Fastest-growing ZIP codes in St. Mary's County, MD

These are the 9 ZIP codes in St. Mary's County with the fastest population growth, out of 9 with at least 1,000 residents. 20670 (Patuxent River, 42.0%), 20653 (Lexington Park, 10.6%) and 20650 (Leonardtown, 9.7%) 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.

Fastest-growing ZIP codes in St. Mary's County

Rank	ZIP	Mailing city	Population change	Residents	Households	Residential mailboxes
1	20670	Patuxent River	42.0%	2,046	439	582
2	20653	Lexington Park	10.6%	26,852	11,028	10,223
3	20650	Leonardtown	9.7%	16,094	5,642	5,712
4	20634	Great Mills	9.4%	7,088	2,694	2,820
5	20659	Mechanicsville	4.3%	24,324	8,300	8,521
6	20636	Hollywood	-3.0%	10,486	3,324	4,096
7	20619	California	-5.6%	14,212	5,719	6,282
8	20620	Callaway	-18.6%	1,115	389	476
9	20622	Charlotte Hall	-24.7%	5,185	1,489	1,585

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; 9 of 27 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 28,103 households, on 47 carrier routes with 27,858 residential mailboxes. Open any of them on the route map to see each carrier route's own figures before you choose.

Open 20670 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 fastest population growth?: 20670 (Patuxent River), at 42.0%, among 9 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.