Market insights · Maryland
St. Mary's County, MD: growth, migration and housing
St. Mary's County has 116,692 residents, up 2.4% since 2020 (+0.4% in the last year). In 2022–2023, 3,107 households moved in and 3,169 moved out (-62 net), while a net $30.0M of income left. Median household income is $119,446, the median home $407,600 and median rent $1,747 a month.
In Maryland: 9th of 24 counties for 5-year population growth · 15th of 24 counties for net in-migration (per resident) · 7th of 24 counties for median household income · 11th of 24 counties for median home value.
Where new residents came from
Top counties by households (tax returns) moving to St. Mary's County, 2022–2023 (IRS).
| From | Households (tax returns) | Their income (AGI) |
|---|---|---|
| Charles County, MD | 462 | $32.4M |
| Calvert County, MD | 315 | $18.7M |
| Prince George's County, MD | 231 | $13.3M |
| Anne Arundel County, MD | 91 | $7.0M |
| San Diego County, CA | 69 | $4.8M |
| Virginia Beach city, VA | 59 | $5.6M |
| Montgomery County, MD | 48 | $3.7M |
| Island County, WA | 45 | $3.0M |
Where leavers went
Top counties by households leaving St. Mary's County, 2022–2023 (IRS).
| To | Households (tax returns) | Their income (AGI) |
|---|---|---|
| Charles County, MD | 326 | $22.5M |
| Calvert County, MD | 295 | $20.7M |
| Prince George's County, MD | 108 | $6.9M |
| Anne Arundel County, MD | 99 | $7.6M |
| Fairfax County, VA | 60 | $5.0M |
| Montgomery County, MD | 50 | $4.3M |
| San Diego County, CA | 49 | $3.4M |
| District of Columbia, DC | 48 | $2.9M |
BizyFi in St. Mary's County
18 companies in the BizyFi directory are based here. Search them on the company map (company names with a free account), or browse Maryland companies.
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Sources: U.S. Census Bureau population estimates (vintage 2025), American Community Survey 5-year (2024), and IRS Statistics of Income county-to-county migration data (2022–2023). Migration counts are tax returns (roughly households) moving between U.S. counties; the IRS suppresses very small flows. Growth rates, per-1,000 figures, rent share and state ranks are BizyFi calculations. Data updated 2026-10-17. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.