Key numbers
- 27.4%of Contra Costa County residents were born outside the U.S. in 2025: 320,444 people (±11,516)Census Bureau, ACS 2025 1-year, table B05002
- 35.9%of Alameda County residents were born outside the U.S. in 2025: 587,246 people (±14,265)Census Bureau, ACS 2025 1-year, table B05002
- about 6,550people living in Contra Costa County became lawful permanent residents in fiscal year 2024 (Alameda County: about 12,100)DHS, new LPRs by county, FY2024
- 24,980people were naturalized as U.S. citizens in fiscal year 2024 in the San Francisco-Oakland-Fremont metro area, which includes both countiesDHS, 2024 Yearbook, Naturalizations Supplemental Table 3
Verified figures on immigrants and immigration cases in the East Bay's two largest counties, Contra Costa and Alameda, from the Census Bureau, the Department of Homeland Security (DHS) and U.S. Citizenship and Immigration Services (USCIS). Every figure gives its source and period. Survey figures are estimates and show a margin of error at 90% confidence; DHS figures are counts that DHS rounds to the nearest 10.
Source: U.S. Census Bureau, American Community Survey 2025 1-year estimates, table B05002.
Residents born outside the United States
In 2025, 320,444 Contra Costa County residents (±11,516) were born outside the United States, 27.4% of the county's 1,170,070 people, close to the California share of 27.2%. In Alameda County the figure was 587,246 (±14,265), 35.9% of 1,636,630 residents. Nationally, 14.7% of residents were born abroad.
64% of Contra Costa's foreign-born residents (203,878, ±11,119) were naturalized U.S. citizens, against 55% in Alameda County and 57% statewide.
| Contra Costa County | Alameda County | California | United States | |
|---|---|---|---|---|
| Population | 1,170,070 | 1,636,630 | 39,355,309 | 341,784,859 |
| Born outside the U.S. | 320,444 | 587,246 | 10,687,553 | 50,409,320 |
| margin of error (±) | 11,516 | 14,265 | 63,533 | 204,810 |
| share of population | 27.4% | 35.9% | 27.2% | 14.7% |
| margin of error (± points) | 1.0 | 0.9 | 0.2 | 0.1 |
| Naturalized U.S. citizens | 203,878 | 321,294 | 6,116,761 | 27,178,573 |
| margin of error (±) | 11,119 | 13,364 | 49,102 | 119,516 |
| share of foreign-born | 63.6% | 54.7% | 57.2% | 53.9% |
| margin of error (± points) | 2.6 | 1.8 | 0.3 | 0.1 |
| Not U.S. citizens | 116,566 | 265,952 | 4,570,792 | 23,230,747 |
| margin of error (±) | 9,880 | 14,390 | 53,977 | 176,208 |
Source: U.S. Census Bureau, American Community Survey 2025 1-year estimates, table B05002. ± is the 90% margin of error; for shares it is in percentage points, calculated with the Census Bureau's formula for a proportion. Total population is controlled to official estimates and has no margin of error.
Change since 2019
Compared with the 2019 one-year survey, Contra Costa's foreign-born population grew by 16,454 (from 303,990), its naturalized citizens by 31,031 (from 172,847), and its foreign-born residents who are not citizens fell by 14,577 (from 131,143). In Alameda County the foreign-born population grew by 45,975 (from 541,271) and non-citizens by 30,460 (from 235,492), while its total population fell from 1,671,329 to 1,636,630. Each of the changes in foreign-born, naturalized and non-citizen residents named here is statistically significant at 90% confidence. Alameda's naturalized citizens also rose, by 15,515, but that change is not statistically significant.
Where East Bay immigrants were born
Mexico is the most common country of birth among Contra Costa's foreign-born residents (71,472, ±3,194), followed by the Philippines and India. In Alameda County, India (102,500, ±3,054) is the most common, ahead of Mexico (90,998). These are 2020-2024 averages, the latest figures by country for single counties.
| Rank | Country of birth | Estimate | Margin of error (±) |
|---|---|---|---|
| 1 | Mexico | 71,472 | 3,194 |
| 2 | Philippines | 35,560 | 2,088 |
| 3 | India | 27,589 | 1,814 |
| 4 | China, excluding Hong Kong and Taiwan | 20,738 | 1,658 |
| 5 | El Salvador | 17,292 | 2,088 |
| 6 | Guatemala | 7,263 | 1,321 |
| 7 | Vietnam | 7,186 | 944 |
| 8 | Korea | 6,884 | 1,024 |
| 9 | Iran | 6,426 | 851 |
| 10 | Taiwan | 5,691 | 678 |
| Rank | Country of birth | Estimate | Margin of error (±) |
|---|---|---|---|
| 1 | India | 102,500 | 3,054 |
| 2 | Mexico | 90,998 | 3,146 |
| 3 | China, excluding Hong Kong and Taiwan | 82,326 | 2,719 |
| 4 | Philippines | 54,949 | 2,849 |
| 5 | Vietnam | 25,563 | 2,038 |
| 6 | Guatemala | 15,014 | 1,818 |
| 7 | Taiwan | 14,812 | 1,091 |
| 8 | El Salvador | 14,547 | 1,387 |
| 9 | Hong Kong | 13,625 | 971 |
| 10 | Korea | 12,619 | 995 |
Source for both tables: U.S. Census Bureau, ACS 5-year estimates 2020-2024, table B05006, every country line (regional subtotals and "other" groups left out). Margins of error are at 90% confidence. In both counties the countries ranked 6 to 10 are within each other's margins of error: each one's 90% range overlaps the next-ranked country's, so their order is not certain. The Census Bureau lists China (excluding Hong Kong and Taiwan), Hong Kong and Taiwan separately.
New green cards
About 6,550 people living in Contra Costa County became lawful permanent residents (green card holders) in fiscal year 2024 (October 2023 to September 2024), and about 12,100 in Alameda County. In Contra Costa the most common countries of birth among them were Mexico (about 1,100) and the Philippines (about 740), followed by China, Afghanistan and India (about 610 to 640 each). In Alameda, India and China were close (about 2,160 and 2,130), followed by Mexico (about 1,580). Across the San Francisco-Oakland-Fremont metro area, 31,150 people became permanent residents.
| County | Fiscal year 2023 | Fiscal year 2024 |
|---|---|---|
| Contra Costa County | about 6,930 | about 6,550 |
| Alameda County | about 13,700 | about 12,100 |
Source: DHS Office of Homeland Security Statistics, New Lawful Permanent Residents by State of Residence, County of Residence, Country of Birth, and Major Class of Admission (top 200 counties), FY2023 and FY2024. DHS rounds each cell to the nearest 10; these totals add the rounded cells, so they are approximate.
| Type | Contra Costa County | Alameda County |
|---|---|---|
| Family | about 3,960 (60%) | about 6,530 (54%) |
| Employment | about 1,020 (16%) | about 2,790 (23%) |
| Refugees and asylees | about 630 (10%) | about 1,440 (12%) |
| Diversity visa | about 210 (3%) | about 220 (2%) |
| Other | about 730 (11%) | about 1,120 (9%) |
Source: as above. Family includes immediate relatives of U.S. citizens and the family preference categories; employment includes the five employment preferences; "other" includes special immigrant and parole-related classes.
Citizenship applications and naturalizations
In fiscal year 2024, 24,980 people were naturalized as U.S. citizens in the San Francisco-Oakland-Fremont metro area (Alameda, Contra Costa, Marin, San Francisco and San Mateo counties); 14,590 of them (58%) were born in Asia or Oceania. The DHS yearbook reports naturalizations by state and metro area, not by county.
| Metro area | New permanent residents | Persons naturalized |
|---|---|---|
| San Francisco-Oakland-Fremont, CA | 31,150 | 24,980 |
| San Jose-Sunnyvale-Santa Clara, CA | 19,420 | 14,010 |
| Sacramento-Roseville-Folsom, CA | 14,020 | 8,070 |
| United States | 1,364,090 | 818,570 |
Source: DHS, 2024 Yearbook of Immigration Statistics, LPR Supplemental Table 2 and Naturalizations Supplemental Tables 2 and 3 (cells rounded to the nearest 10). Metro areas follow the 2023 Census Bureau delineation.
Citizenship applications (Form N-400) are decided at USCIS field offices. From April to June 2026, the San Francisco field office approved 338 applications and had 18,645 waiting at the end of June. Nationally, the median processing time for a citizenship application was 9.5 months in that quarter, up from 5.5 months a year earlier. Our study of naturalization backlogs at Bay Area and Sacramento USCIS offices tracks these offices quarter by quarter.
| Field office | Received, Apr-Jun 2026 | Approved, Apr-Jun 2026 | Denied, Apr-Jun 2026 | Pending, June 30, 2026 | Approved, Apr-Jun 2025 | Pending, June 30, 2025 |
|---|---|---|---|---|---|---|
| San Francisco | 3,214 | 338 | 64 | 18,645 | 5,506 | 10,209 |
| San Jose | 4,685 | 317 | 91 | 20,899 | 9,041 | 9,580 |
| Sacramento | 2,466 | 489 | 148 | 15,918 | 3,345 | 11,603 |
Source: USCIS, Form N-400 by category, case status and field office, FY2026 Q3 and FY2025 Q3. USCIS assigns cases to offices by ZIP code; this page does not say which office handles a particular address.
Afghan-born residents
An estimated 7,741 people born in Afghanistan lived in Alameda County in 2020 to 2024 (±1,306) and 4,732 in Contra Costa County (±914). In fiscal year 2024, about 780 Afghanistan-born residents of Alameda County and about 620 of Contra Costa County became permanent residents.
Method
Census figures come from the Census Bureau's data API: table B05002 for 2025 and 2019 (one-year surveys) and table B05006 for 2020-2024 (five-year). Changes since 2019 are called significant only when they pass the Census Bureau's 90% test. DHS county figures add the published cells for each county; metro-area and national figures are DHS's own totals. USCIS field office figures are those in our naturalization study.
A script computes every figure on this page from the downloaded files. A separate check script pulls the headline figures again from the Census API, DHS and USCIS and confirms they match.
Sources
- U.S. Census Bureau, American Community Survey 1-year estimates, table B05002, Place of Birth by Nativity and Citizenship Status
- U.S. Census Bureau, American Community Survey 1-year estimates, table B05002
- U.S. Census Bureau, American Community Survey 5-year estimates, table B05006, Place of Birth for the Foreign-Born Population
- DHS Office of Homeland Security Statistics, New Lawful Permanent Residents by State of Residence, County of Residence, Country of Birth, and Major Class of Admission (Top 200 Counties)
- DHS Office of Homeland Security Statistics, 2024 Yearbook of Immigration Statistics: LPR Supplemental Table 2; Naturalizations Supplemental Tables 2 and 3
- USCIS, Form N-400 by category, case status and USCIS field office location (quarterly)
- U.S. Census Bureau, Core Based Statistical Areas delineation file (List 1), July 2023
Limits of this data
- ACS figures are survey estimates with margins of error. One-year figures (2025, 2019) are the most current; country-of-birth figures for single counties need the five-year survey (2020-2024).
- DHS rounds every cell to the nearest 10, so the county green card totals, which add many cells, are approximate.
- The DHS yearbook reports naturalizations by state and metro area, not by county. The San Francisco-Oakland-Fremont metro area includes three counties outside the East Bay.
- The plan for this page included USCIS's current processing times for each field office and the State Department's monthly immigrant visa issuances. Both websites block automated access, so those figures are not here; the national median processing time comes from USCIS's quarterly report instead.
- USCIS assigns cases to field offices by ZIP code, and its office pages now redirect to a locator, so this page does not say which office serves which East Bay city.
Cite this page
Joya Law Firm, "East Bay Immigration Statistics," published November 12, 2026, https://joya.law/research/east-bay-immigration-statistics/. Data: U.S. Census Bureau, U.S. Department of Homeland Security, U.S. Citizenship and Immigration Services.
Download the data: east-bay-immigration-statistics.csv (every figure on this page, with source and margin of error). The data files are free to reuse under the Creative Commons Attribution 4.0 license (CC BY 4.0); please credit Joya Law Firm and link to this page.