In April 2024, Maryland’s comptroller issued a “State of the Economy” brief spotlighting immigration.  Despite its size, Maryland’s foreign-born population proportion tops the U.S. average (13.9% in 2022), a position the state achieved in the 2000s and has maintained.

Population Dynamics

Maryland’s overall population growth since 2016 increasingly relied on international migration, even as the state kept losing domestic residents to other states.  By 2022–2024, immigrants were roughly one in six Marylanders, and reputable estimates put the unauthorized (illegal alien) population at over 370,000 in 2023.

In 2022, 16.7% were foreign-born (≈1.03 million), according to the comptroller’s report.  For comparison, a 2023 map on the Maryland Planning page shows a slight rise in foreign-born residents at 17.0%.

Another reference for the foreign-born numbers in Maryland is the 2024 American Community Survey (ACS) roll-up, compiled by USAFacts, which puts the numbers at about 17.1%.  ACS is the Census Bureau’s continuous survey that publishes 1-year and 5-year estimates on population, housing, income, country of origin, etc.

Taken together, these sources show steady growth in the immigrant share.  The comptroller notes a mere ~1% increase for the U.S.-born population versus a ~12% increase for the foreign-born population (2016–2022).  The brief also reports that from 2022 to 2023, Maryland ranked among the top states for net immigrant gains (nearly 33,000).

Illegal residents in Maryland

The comptroller emphasizes that international migration flipped Maryland from flat or negative growth to positive in 2023, offsetting persistent domestic out-migration.  The comptroller’s immigration brief also references illegal residents in Maryland (2021stats).  The statistics below are found in Figure 7 in the report:

• 55% of Maryland’s immigrants were naturalized; 45% were unnaturalized.

• Of that unnaturalized group, 36% were “unauthorized” (illegal); the rest were green card–holders, temporary workers, students, refugees, TPS/DACA, diplomats, etc.

In summary, the comptroller’s report shows that in 2021, 36% of the state’s unnaturalized immigrants were unauthorized, meaning they were illegal — which works out to 16.2% of Maryland’s immigrant population, about 2.5–3% of the total population.

Independent Statewide Estimates (MPI)

Another resource for immigration data is the Migration Policy Institute (MPI), a standard state-level reference for immigration data.  It models Maryland’s illegal alien population at ~373,000 in 2023, including visa overstays and people in liminal statuses (e.g., DACA, TPS, pending asylum).  MPI also shows data for the top origins of illegal aliens.  El Salvador (120,000) Guatemala (68,000), Honduras (42,000), Mexico (23,000), and Nigeria (10,000) are in the top 5 spots.

Per MPI modeling, 119,000 of the illegal residents have been in Maryland for 20 years or more, and 60,000 have been in the state for 15 to 19 years.  The largest age cohort in terms of years of U.S. residence comprises 35- to 44-year-olds, at 107,000.  About 45% of the illegal aliens are female, according to MPI.

According to the chart, roughly 100,000 undocumented Marylanders ages 5–24 are enrolled in school or college.  About 158,000 aged 5+ barely speak English.  An estimated 130,000 — about 35% — own their homes; roughly 198,000 (53%) are uninsured; and around 220,000 live at or above the poverty line, with about 7% in deep poverty (below 50% of the poverty threshold).

The comptroller’s brief and MPI’s statewide numbers reflect different lenses, methods, and source data.  The comptroller synthesizes figures from multiple federal and advocacy datasets, whereas MPI models legal status by imputing it from ACS microdata, the Survey of Income and Program Participation (SIPP), and DHS flow data.  SIPP is the go-to panel survey for tracking how people’s income and program use change over time, and it is a key ingredient in modeling the size and characteristics of the illegal alien population.  The two can be reported side by side as complementary, but MPI’s figures are the more widely cited for the number of illegal aliens in Maryland.

According to the Maryland comptroller, the migrant population is generally concentrated in Montgomery, Prince George’s, and Howard Counties, and illegal residents follow similar patterns, with large Central American communities.

Migrants make up 21.1% of Maryland’s labor force (2022), with over-representation in physically demanding fields like construction, where 12% of foreign-born residents are employed, a sector in which illegal aliens are common.  Only 5.8% of U.S.-born Marylanders work in construction.

Labor participation rates (LPR) for foreign-born Marylanders “has ranged from 7 to 9 percent percentage points higher than the LPR for U.S.-born Marylanders,” according to the Figure 11 of the report.

Implications for Maryland’s elections

Illegal immigration can strain housing, schools, and health care, and it may also carry implications for Maryland elections.  Kate Sullivan’s citizen-led volunteer group, Secure the Vote Maryland, organized two voter canvasses using data from the 2020 and 2022 elections.  One canvass was in Baltimore County, and the other was statewide.  The group’s work alleges the state’s voter rolls contain upwards of “79k inaccurate records” in addition to other troubling ineligible records.  Sullivan adds that her group is working with the State Board of Elections, Maryland’s Freedom Caucus, and now the Department of Justice to ensure elections to improve list accuracy.

Referencing the comptroller’s State of the Economy brief, lead data analyst for Secure the Vote MD David Morsberger sees a puzzling pattern.  Voter registrations are rising even as Maryland posts net losses from domestic out-migration.  The discrepancy could indicate ineligible registrations, potentially including illegal aliens remaining on the rolls and, in some cases, voting.

Nevertheless, the State Board of Elections (SBE) has told Secure the Vote that non-citizens cannot vote in Maryland and that the rolls are properly maintained.  The Maryland Freedom Caucus, however, says it identified at least one example that contradicts the SBE’s claims.  Using official state records, the caucus claims that a former Iowa superintendent arrested by immigration authorities for overstaying a visa is still listed as an active Maryland voter.

Although the SBE may believe that the state’s voter rolls are properly maintained, a July 14, 2025 letter from the Civil Rights Division of the DOJ underscores list maintenance concerns.  For one, the DOJ cites unusually high registration rates — 95.9% of the citizen voting-age population (CVAP) in 2024, ~94% in 2022, and 96% in 2020, levels that can indicate list inflation when combined with sustained out-migration.  The DOJ also notes 6,491,862 registration transactions despite 4,231,112 active voters and asks SBE to reconcile the gap.  High rates of this sort can indicate list inflation when combined with out-migration, a known vector for voter fraud in elections.

The DOJ further questions whether SBE is adequately acting on confirmation notices and audit findings.  Maryland sent 1,559,430 address confirmation notices (36.9% of actives), and 97.5% went unreturned, yet comparatively few records were made inactive or removed.  DOJ also flags a discrepancy in new registrations: 524,189 “new valid registrations” vs. 613,352 listed on SBE’s year-end activity reports for 2023 and 2024 combined.  Please read Maryland’s July 30, 2025 SBE response here.

Though not conclusive, large gaps of this kind can mask duplicates, movers, deceased registrants, and other ineligible entries — issues that are provably documented in Secure the Vote Maryland’s canvass report and highlighted in the DOJ’s letter.

In a follow-up interview, Sullivan said her team has submitted to the Maryland state prosecutor the “fully verified and vetted duplicate and deceased registrations that were clearly used to vote since 2018.”  She added, “It appears that the Office of the Special Prosecutor (OSP) has totally ignored” the submissions.

According to Sullivan, there were 29 voters who used deceased records to vote since 2018 (10 in 2024) and 42 voters who used duplicate registrations to vote since 2018 (15 in 2024).  “In most cases, these people are repeat offenders,” she said.  “And the office of the special prosecutor has done NOTHING.”

Baltimore skyline via Pexels.