Proposition 13 Lock-In by City: How Old Is the Tax Base Where You Live?
Proposition 13 taxes a home on the value it had when it last changed hands, grown at most 2% a year. So two identical houses on one street can pay very different bills, and a city where few homes have sold since the 1970s carries a tax base far older than its prices. This page measures that, city by city, from the assessors' own parcel data: the share of single-family homes and condominiums still on a pre-1980 base year (the 1975 roll value, or a 1975–79 purchase price), the share set in each later decade, the median base year, the share claiming the Homeowners' Exemption (a proxy for owner-occupancy) and the median taxable value. It adds the Riverside Assessor's 22-year series, the Santa Clara Assessor's published table, and Homeowners' Exemption claims per 100 owner-occupied homes for all 58 counties.
Quick answer
In the City of Los Angeles, 10.2% of 626,301 homes and condos still carry a base year before 1980 and the median base year is 2009. Among LA County's incorporated cities the pre-1980 share runs from 19.1% in Montebello to 1.5% in Palmdale; in San Bernardino County it peaks at 10.7% (Needles). Riverside County's roll shows the lock-in eroding: parcels still on a 1975 base fell from 6.8% of assessments in 2004-2005 to 1.6% in 2026-2027, and pre-2000 base years from 43% of assessed value to 6%. Statewide, 4,636,214 homes claimed the Homeowners' Exemption in 2025–26, down from 5,207,251 in 2000–01, about 61 claims per 100 owner-occupied homes.
How to read the tables
Each row is one city (or an unincorporated community the roll names): the number of single-family homes and condos, the share whose year falls in each decade, the median year, the exemption share and the median taxable value. What “year” means depends on what the county publishes, so the tables are split in two.
| County | What the year column is | Exemption column | Data vintage | Confidence |
|---|---|---|---|---|
| Los Angeles | Land Base Year on the 2025 roll | Homeowners' Exemption claimed | 2025 roll | high |
| San Bernardino | BASE_YEAR field on the Assessor's parcel layer | Homeowners' Exemption flag | current layer, read 2026-10-24 (no roll year stated) | medium-high |
| Fresno | Base_Year field on a 2022 parcel layer; use-code filter unverified | Homeowners' Exemption amount > 0 | 2022 layer | low |
| Sacramento | Date the current enrolled value was set (VALUE_DT); 1975 marks the original Prop 13 base | Homeowners' Exemption amount > 0 | Assessor extract of 2026-08-29 | medium |
| San Francisco | Year of the most recent recorded sale (current_sales_date); the source starts in 1983, so there is no pre-1980 bin and about a quarter of parcels have no date | Homeowners' Exemption value > 0 | 2025 roll (series back to 2007) | medium |
| San Diego | Year of the latest recorded document of any kind (DOCDATE), not a base year | Owner-occupied indicator (OWNEROCC), not the exemption | layer read 2026-10-24 | low |
| Alameda | Latest recorded document date of any kind (LatestDocumentDate) | Homeowners' Exemption amount > 0 | layer read 2026-10-24 | low-medium |
| Contra Costa | Year of the current recorded deed (C_DED_DateStr; no county definition, but it matches the recorder document number's year in 98% of 1994+ rows and runs to August 2026, so it is a deed date, not a base year) | Exemption code HO | live layer read 2026-10-24, carrying 2026-27 roll values | low-medium |
Ventura is left out: The only date field (DT_V_TRF_Y) has no published meaning and reads as a recent value event in every city (44–50% dated 2020 or later), and the layer has no exemption field. Kern, Riverside, San Mateo, Santa Clara and Orange publish parcel layers with no year or exemption field (Riverside and Santa Clara appear below from their assessors' reports instead). Cells built from fewer than 30 homes are suppressed; LA communities with fewer than 1,000 homes are not listed.
Counties with a true base year on the roll
Here the year is the Proposition 13 base year the assessor carries (Sacramento: the date the current value was set), so the pre-1980 column is the share of homes taxed on a 1975 value. Within each county, cities are ordered by that share. In Los Angeles County, neighbourhood names the roll sometimes writes for parcels inside the City of Los Angeles (Woodland Hills, San Pedro, Northridge …) are folded into the city; unincorporated communities (Altadena, Hacienda Heights, Rowland Heights …) have their own rows, marked “community”.
| City | Homes | Pre-1980 | 1980s | 1990s | 2000s | 2010s | 2020+ | Median base year | Exemption / owner-occupied share | Median taxable value |
|---|---|---|---|---|---|---|---|---|---|---|
| Los Angeles County — 93 cities and communities; year = Land Base Year on the 2025 roll; exemption column = Homeowners' Exemption claimed; 2025 roll; confidence high. | ||||||||||
| Montebello | 10,093 | 19.1% | 10.3% | 12.8% | 17.9% | 22.9% | 16.9% | 2003 | 53.6% | $369,253 |
| Pico Rivera | 13,004 | 18.8% | 10.3% | 13.5% | 19.6% | 22.5% | 15.3% | 2003 | 49.8% | $315,611 |
| South El Monte | 2,610 | 18.4% | 9.8% | 12.4% | 17.4% | 21.9% | 20.1% | 2004 | 49.2% | $338,666 |
| Cerritos | 15,277 | 17.4% | 14.3% | 16.8% | 19.1% | 20.2% | 12.3% | 2000 | 58.2% | $470,145 |
| Monterey Park | 13,826 | 16.8% | 10.2% | 12.1% | 21.4% | 23.2% | 16.2% | 2004 | 55.2% | $455,125 |
| Santa Fe Springs | 3,764 | 15.9% | 7.6% | 12.5% | 16.1% | 30.0% | 17.8% | 2008 | 47.4% | $383,644 |
| Rancho Palos Verdes | 14,619 | 15.9% | 10.2% | 14.5% | 16.8% | 23.6% | 19.0% | 2004 | 59.6% | $938,363 |
| Commerce | 1,698 | 15.8% | 13.0% | 14.0% | 21.9% | 19.0% | 16.3% | 2003 | 46.8% | $285,222 |
| Artesia | 3,345 | 15.4% | 9.5% | 12.5% | 21.7% | 23.2% | 17.6% | 2005 | 44.8% | $396,099 |
| Carson | 21,052 | 15.3% | 10.4% | 14.3% | 20.9% | 23.2% | 15.9% | 2004 | 49.8% | $346,233 |
| Gardena | 12,372 | 15.3% | 7.1% | 12.3% | 19.7% | 24.4% | 21.2% | 2006 | 51.0% | $388,874 |
| Altadena (community) | 10,713 | 14.6% | 9.9% | 15.1% | 18.4% | 24.2% | 17.8% | 2004 | 56.0% | $366,829 |
| Palos Verdes Estates | 5,109 | 14.4% | 10.0% | 14.6% | 16.2% | 24.1% | 20.7% | 2005 | 58.2% | $1,640,697 |
| Torrance | 40,613 | 14.2% | 10.1% | 15.3% | 19.2% | 23.0% | 18.3% | 2004 | 56.8% | $579,421 |
| Sierra Madre | 3,391 | 14.1% | 10.7% | 13.8% | 16.3% | 24.2% | 20.9% | 2006 | 57.1% | $720,794 |
| Compton | 20,580 | 13.8% | 7.3% | 11.0% | 21.4% | 27.7% | 18.8% | 2007 | 42.3% | $258,364 |
| Lakewood | 23,115 | 13.6% | 9.0% | 14.8% | 18.8% | 24.6% | 19.3% | 2005 | 51.2% | $452,098 |
| Manhattan Beach | 11,067 | 13.3% | 10.0% | 15.3% | 18.2% | 24.1% | 19.0% | 2005 | 53.7% | $1,490,249 |
| Maywood | 1,593 | 12.9% | 14.6% | 16.1% | 25.8% | 19.4% | 11.2% | 2002 | 46.8% | $266,520 |
| San Fernando | 3,898 | 12.9% | 11.3% | 14.3% | 21.1% | 24.8% | 15.5% | 2004 | 43.9% | $313,697 |
| Whittier | 41,307 | 12.8% | 9.6% | 14.6% | 19.0% | 24.6% | 19.4% | 2005 | 48.1% | $416,723 |
| Rosemead | 8,703 | 12.6% | 12.4% | 16.5% | 22.4% | 21.9% | 14.2% | 2003 | 54.1% | $411,477 |
| La Puente | 22,988 | 12.5% | 10.5% | 14.8% | 22.3% | 24.1% | 15.7% | 2004 | 48.0% | $327,714 |
| Norwalk | 21,281 | 12.4% | 8.7% | 13.7% | 22.3% | 26.2% | 16.7% | 2005 | 45.1% | $344,969 |
| La Mirada | 13,576 | 12.3% | 9.1% | 16.4% | 18.4% | 24.8% | 19.0% | 2005 | 51.8% | $457,139 |
| South Pasadena | 5,493 | 12.1% | 11.0% | 14.9% | 19.1% | 25.5% | 17.4% | 2005 | 57.6% | $747,615 |
| Burbank | 22,027 | 11.8% | 9.0% | 14.5% | 19.8% | 25.8% | 19.0% | 2007 | 52.2% | $581,625 |
| Rolling Hills Estates | 3,154 | 11.8% | 9.9% | 12.9% | 17.5% | 24.3% | 23.6% | 2008 | 56.9% | $1,122,683 |
| Inglewood | 15,739 | 11.8% | 11.0% | 15.6% | 22.5% | 23.0% | 16.2% | 2004 | 48.9% | $313,693 |
| Lomita | 3,845 | 11.8% | 9.0% | 13.7% | 19.0% | 24.6% | 22.0% | 2007 | 52.4% | $524,477 |
| Culver City | 10,349 | 11.7% | 10.5% | 14.5% | 18.8% | 24.0% | 20.5% | 2006 | 55.8% | $555,334 |
| Glendora | 14,390 | 11.7% | 10.7% | 14.2% | 17.0% | 25.8% | 20.6% | 2007 | 52.3% | $516,819 |
| Hacienda Heights (community) | 12,096 | 11.6% | 11.9% | 15.7% | 21.0% | 23.2% | 16.6% | 2004 | 52.4% | $470,290 |
| San Marino | 4,459 | 11.4% | 11.0% | 17.1% | 21.6% | 21.4% | 17.5% | 2003 | 57.7% | $1,568,398 |
| Valinda (community) | 1,732 | 11.3% | 11.6% | 14.5% | 24.9% | 21.3% | 16.3% | 2003 | 46.4% | $321,270 |
| La Canada Flintridge | 6,779 | 11.2% | 9.3% | 15.6% | 17.6% | 26.8% | 19.6% | 2007 | 58.8% | $1,279,927 |
| El Segundo | 3,493 | 11.1% | 9.2% | 15.2% | 18.2% | 24.6% | 21.7% | 2007 | 54.5% | $800,219 |
| Beverly Hills | 8,127 | 10.8% | 8.3% | 15.7% | 19.8% | 24.9% | 20.4% | 2006 | 41.2% | $1,964,557 |
| La Crescenta Montrose (community) | 5,367 | 10.7% | 8.7% | 14.6% | 20.0% | 27.2% | 18.9% | 2007 | 54.9% | $686,809 |
| Alhambra | 14,266 | 10.6% | 11.4% | 15.6% | 22.4% | 23.8% | 16.2% | 2004 | 53.4% | $446,031 |
| La Habra Heights | 1,879 | 10.6% | 11.3% | 14.3% | 17.7% | 23.6% | 22.4% | 2006 | 53.3% | $881,372 |
| San Gabriel | 12,135 | 10.4% | 9.8% | 16.2% | 23.4% | 24.5% | 15.8% | 2004 | 55.1% | $546,721 |
| Temple City | 9,016 | 10.3% | 9.1% | 16.2% | 23.4% | 25.3% | 15.7% | 2005 | 57.1% | $583,024 |
| West Covina | 25,255 | 10.3% | 10.5% | 16.0% | 21.0% | 25.2% | 17.1% | 2005 | 52.6% | $418,955 |
| Covina | 18,754 | 10.2% | 9.2% | 14.8% | 20.3% | 26.2% | 19.3% | 2007 | 48.6% | $413,164 |
| Claremont | 9,654 | 10.2% | 9.7% | 13.6% | 18.7% | 26.1% | 21.7% | 2008 | 53.2% | $557,860 |
| Los Angeles | 626,301 | 10.2% | 8.1% | 12.9% | 19.5% | 27.3% | 22.0% | 2009 | 45.5% | $515,745 |
| Huntington Park | 5,560 | 10.1% | 13.6% | 15.1% | 24.5% | 21.7% | 15.1% | 2004 | 43.3% | $287,195 |
| Lynwood | 7,263 | 10.0% | 10.9% | 15.4% | 25.7% | 24.5% | 13.5% | 2004 | 43.8% | $287,120 |
| Hawthorne | 11,108 | 9.9% | 8.0% | 15.6% | 22.0% | 27.3% | 17.3% | 2007 | 49.9% | $441,994 |
| Monrovia | 8,658 | 9.9% | 9.0% | 14.6% | 19.6% | 27.3% | 19.7% | 2008 | 53.7% | $527,937 |
| Baldwin Park | 12,931 | 9.8% | 11.4% | 13.6% | 23.9% | 25.2% | 16.1% | 2005 | 47.9% | $304,561 |
| Downey | 19,846 | 9.7% | 8.0% | 15.1% | 22.2% | 28.0% | 16.9% | 2007 | 46.4% | $470,792 |
| Long Beach | 80,119 | 9.7% | 7.8% | 13.8% | 20.1% | 27.1% | 21.5% | 2009 | 46.8% | $428,434 |
| Duarte | 6,475 | 9.7% | 12.2% | 14.9% | 21.3% | 24.6% | 17.4% | 2005 | 51.0% | $377,841 |
| La Verne | 8,762 | 9.6% | 12.7% | 15.7% | 17.6% | 24.9% | 19.5% | 2005 | 53.2% | $491,214 |
| El Monte | 13,121 | 9.6% | 9.9% | 15.4% | 24.6% | 25.5% | 15.0% | 2004 | 52.4% | $354,633 |
| Pasadena | 35,870 | 9.6% | 9.3% | 13.6% | 18.5% | 27.2% | 21.9% | 2009 | 49.4% | $620,275 |
| Lawndale | 3,761 | 9.6% | 7.8% | 15.2% | 22.9% | 25.8% | 18.8% | 2006 | 47.8% | $393,672 |
| Hermosa Beach | 5,114 | 9.5% | 9.3% | 15.2% | 19.4% | 25.8% | 20.8% | 2007 | 48.9% | $1,122,000 |
| Topanga (community) | 2,037 | 9.4% | 9.6% | 11.5% | 18.2% | 24.7% | 26.6% | 2011 | 44.9% | $807,452 |
| Malibu | 6,807 | 9.4% | 8.1% | 12.6% | 16.0% | 26.0% | 27.9% | 2012 | 31.6% | $1,500,873 |
| Bell | 2,029 | 8.9% | 13.9% | 18.0% | 22.7% | 23.2% | 13.3% | 2003 | 46.0% | $296,070 |
| Bellflower | 10,096 | 8.8% | 7.9% | 14.4% | 22.6% | 28.6% | 17.6% | 2007 | 45.2% | $401,433 |
| Azusa | 11,903 | 8.6% | 7.8% | 11.8% | 19.6% | 31.8% | 20.4% | 2010 | 43.5% | $372,523 |
| South Gate | 10,607 | 8.6% | 13.1% | 15.4% | 25.9% | 23.5% | 13.6% | 2004 | 44.3% | $312,724 |
| Santa Monica | 16,646 | 8.5% | 9.2% | 16.8% | 18.9% | 24.1% | 22.6% | 2007 | 46.2% | $945,206 |
| San Dimas | 9,280 | 8.4% | 13.0% | 15.6% | 17.2% | 26.2% | 19.7% | 2006 | 53.0% | $496,073 |
| Glendale | 33,004 | 8.3% | 8.7% | 15.6% | 21.3% | 27.2% | 18.9% | 2007 | 49.4% | $583,780 |
| Arcadia | 17,560 | 8.2% | 8.3% | 14.3% | 22.8% | 26.0% | 20.4% | 2008 | 52.8% | $798,452 |
| Bell Gardens | 1,362 | 8.2% | 11.8% | 17.4% | 26.8% | 21.7% | 14.1% | 2003 | 43.3% | $282,499 |
| Hawaiian Gardens | 1,751 | 8.2% | 9.3% | 11.2% | 25.7% | 29.1% | 16.6% | 2008 | 35.8% | $266,507 |
| Redondo Beach | 18,546 | 8.0% | 8.5% | 13.8% | 20.4% | 28.4% | 20.9% | 2009 | 52.9% | $802,765 |
| Westlake Village | 3,281 | 7.4% | 8.0% | 16.6% | 15.2% | 27.8% | 25.0% | 2011 | 51.2% | $820,296 |
| Paramount | 5,828 | 6.9% | 9.0% | 14.5% | 24.4% | 28.0% | 17.1% | 2007 | 39.5% | $295,955 |
| Rowland Heights (community) | 8,646 | 6.8% | 12.2% | 19.1% | 22.9% | 23.5% | 15.4% | 2003 | 53.1% | $534,833 |
| Pomona | 27,082 | 6.3% | 8.7% | 13.2% | 22.1% | 30.9% | 18.8% | 2009 | 40.1% | $316,288 |
| Agoura Hills | 6,867 | 5.4% | 14.1% | 15.8% | 17.6% | 26.2% | 20.8% | 2007 | 54.2% | $666,229 |
| Diamond Bar | 17,649 | 5.1% | 13.1% | 15.2% | 21.0% | 26.9% | 18.7% | 2007 | 50.0% | $520,619 |
| Walnut | 10,245 | 4.9% | 16.9% | 19.3% | 20.7% | 23.2% | 15.0% | 2003 | 57.3% | $612,919 |
| Calabasas | 8,544 | 4.7% | 7.8% | 17.9% | 21.2% | 26.2% | 22.0% | 2008 | 49.7% | $999,761 |
| Quartz Hill (community) | 2,197 | 4.5% | 7.4% | 11.2% | 17.4% | 29.6% | 29.9% | 2013 | 42.4% | $351,365 |
| Santa Clarita | 68,206 | 3.5% | 6.6% | 10.6% | 19.6% | 30.8% | 29.0% | 2014 | 46.1% | $541,213 |
| Acton (community) | 2,547 | 3.1% | 8.7% | 12.8% | 19.0% | 26.0% | 30.4% | 2013 | 41.1% | $535,192 |
| Littlerock (community) | 3,565 | 2.9% | 8.0% | 11.7% | 20.5% | 31.6% | 25.2% | 2012 | 31.4% | $226,782 |
| Lancaster | 44,588 | 2.6% | 3.4% | 7.8% | 18.8% | 36.5% | 30.9% | 2015 | 31.9% | $286,841 |
| West Hollywood | 6,838 | 1.8% | 5.4% | 10.7% | 17.4% | 32.2% | 32.6% | 2015 | 35.3% | $724,492 |
| Signal Hill | 2,621 | 1.6% | 4.7% | 9.7% | 23.8% | 33.0% | 27.1% | 2013 | 46.6% | $514,685 |
| Palmdale | 43,478 | 1.5% | 3.5% | 10.5% | 21.6% | 37.0% | 25.9% | 2013 | 35.2% | $300,747 |
| Castaic (community) | 5,619 | 1.0% | 5.4% | 10.8% | 27.3% | 28.2% | 27.3% | 2012 | 46.8% | $547,973 |
| Stevenson Ranch (community) | 3,586 | 0.5% | 0.3% | 12.9% | 31.4% | 34.1% | 20.9% | 2011 | 50.4% | $681,962 |
| Marina Del Rey (community) | 1,002 | 0.3% | 0.9% | 1.0% | 14.7% | 54.3% | 28.9% | 2018 | 23.9% | $923,645 |
| Lake Los Angeles (community) | 1,495 | 0.3% | 6.9% | 10.6% | 19.5% | 35.6% | 27.2% | 2013 | 29.4% | $178,685 |
| San Bernardino County — 25 cities and communities; year = BASE_YEAR field on the Assessor's parcel layer; exemption column = Homeowners' Exemption flag; current layer, read 2026-10-24 (no roll year stated); confidence medium-high. | ||||||||||
| Needles | 1,207 | 10.7% | 5.1% | 7.5% | 15.7% | 31.1% | 29.9% | 2014 | 33.3% | $95,724 |
| Barstow | 5,075 | 8.5% | 3.6% | 6.0% | 17.7% | 30.7% | 33.5% | 2015 | 33.7% | $136,609 |
| Redlands | 18,722 | 7.0% | 7.1% | 10.3% | 19.3% | 28.3% | 28.0% | 2012 | 48.8% | $403,088 |
| Colton | 10,092 | 6.9% | 5.5% | 11.1% | 21.3% | 31.3% | 23.9% | 2011 | 39.8% | $236,539 |
| Montclair | 6,681 | 6.9% | 6.0% | 12.2% | 24.6% | 31.3% | 19.1% | 2010 | 42.7% | $324,278 |
| Upland | 18,448 | 6.4% | 7.9% | 11.2% | 18.5% | 29.3% | 26.7% | 2012 | 48.9% | $493,745 |
| Grand Terrace | 3,286 | 5.6% | 5.1% | 15.9% | 17.6% | 29.3% | 26.5% | 2012 | 45.2% | $320,177 |
| San Bernardino | 39,288 | 5.2% | 4.0% | 8.6% | 20.7% | 34.6% | 27.0% | 2013 | 36.1% | $240,091 |
| Chino | 21,406 | 5.0% | 5.3% | 9.6% | 18.9% | 33.2% | 28.0% | 2013 | 44.0% | $479,437 |
| Big Bear Lake | 8,514 | 4.6% | 4.8% | 7.8% | 13.7% | 29.0% | 40.2% | 2017 | 5.7% | $421,013 |
| Ontario | 39,279 | 4.4% | 5.0% | 9.8% | 17.1% | 30.4% | 33.3% | 2015 | 39.0% | $402,492 |
| Rialto | 20,651 | 3.7% | 5.3% | 11.7% | 22.9% | 32.8% | 23.7% | 2011 | 41.5% | $283,048 |
| Unincorporated (unincorporated) | 101,692 | 3.7% | 4.1% | 8.0% | 17.4% | 31.6% | 35.2% | 2016 | 27.8% | $273,300 |
| Loma Linda | 5,176 | 3.7% | 6.5% | 9.6% | 23.1% | 27.4% | 29.7% | 2012 | 37.2% | $406,331 |
| Yucaipa | 13,183 | 3.4% | 4.6% | 9.1% | 21.0% | 31.9% | 30.0% | 2014 | 47.3% | $380,909 |
| Twentynine Palms | 5,027 | 3.3% | 4.0% | 5.8% | 16.7% | 28.3% | 41.9% | 2018 | 26.8% | $159,079 |
| Rancho Cucamonga | 44,524 | 3.2% | 6.1% | 10.9% | 22.8% | 31.9% | 25.1% | 2012 | 45.0% | $485,830 |
| Highland | 12,614 | 2.5% | 2.1% | 13.0% | 24.0% | 32.6% | 25.8% | 2012 | 44.0% | $335,655 |
| Yucca Valley | 7,633 | 2.2% | 3.5% | 5.4% | 15.8% | 34.1% | 39.0% | 2017 | 36.3% | $232,038 |
| Fontana | 47,375 | 1.8% | 2.8% | 8.8% | 25.2% | 34.8% | 26.6% | 2013 | 41.3% | $396,572 |
| Hesperia | 25,826 | 1.7% | 3.7% | 5.8% | 19.9% | 36.0% | 33.0% | 2015 | 36.8% | $266,935 |
| Chino Hills | 21,899 | 1.6% | 5.9% | 17.2% | 23.4% | 29.4% | 22.5% | 2010 | 49.8% | $561,915 |
| Apple Valley | 21,861 | 1.3% | 3.8% | 6.5% | 17.9% | 35.1% | 35.5% | 2016 | 42.4% | $284,458 |
| Victorville | 33,027 | 0.7% | 1.5% | 4.7% | 19.0% | 38.5% | 35.6% | 2016 | 32.6% | $266,361 |
| Adelanto | 7,956 | 0.2% | 0.2% | 4.5% | 20.7% | 42.4% | 32.0% | 2015 | 32.0% | $224,317 |
| Fresno County — 16 cities and communities; year = Base_Year field on a 2022 parcel layer; use-code filter unverified; exemption column = Homeowners' Exemption amount > 0; 2022 layer; confidence low. | ||||||||||
| Mendota | 1,756 | 10.9% | 8.3% | 12.6% | 21.6% | 34.6% | 12.0% | 2008 | 41.0% | $131,017 |
| Unincorporated (unincorporated) | 40,396 | 10.1% | 8.4% | 14.9% | 20.1% | 32.0% | 14.4% | 2007 | 38.0% | $209,005 |
| Orange Cove | 1,398 | 8.6% | 6.4% | 19.6% | 23.5% | 34.5% | 7.5% | 2005 | 36.6% | $116,791 |
| Firebaugh | 1,482 | 6.7% | 4.3% | 22.0% | 22.8% | 28.5% | 15.6% | 2006 | 41.1% | $134,810 |
| Parlier | 2,437 | 6.3% | 10.3% | 15.2% | 23.8% | 33.0% | 11.4% | 2007 | 39.8% | $128,875 |
| Sanger | 5,586 | 5.5% | 5.9% | 12.1% | 22.4% | 40.2% | 13.9% | 2010 | 35.6% | $182,408 |
| Reedley | 4,796 | 5.4% | 6.0% | 18.4% | 25.0% | 31.2% | 14.0% | 2008 | 41.4% | $180,847 |
| Kerman | 3,205 | 5.2% | 3.8% | 10.6% | 27.2% | 37.5% | 15.8% | 2010 | 35.3% | $208,320 |
| Fowler | 1,838 | 5.1% | 5.7% | 10.8% | 25.9% | 33.2% | 19.3% | 2011 | 34.9% | $231,853 |
| Huron | 719 | 4.0% | 13.1% | 22.4% | 28.2% | 17.6% | 14.7% | 2003 | 35.5% | $111,058 |
| Selma | 5,000 | 3.9% | 5.6% | 16.5% | 23.9% | 37.6% | 12.5% | 2010 | 37.2% | $167,006 |
| Kingsburg | 3,403 | 3.7% | 5.7% | 13.8% | 25.3% | 33.0% | 18.5% | 2010 | 40.5% | $238,645 |
| Coalinga | 2,956 | 3.6% | 4.6% | 13.0% | 21.6% | 37.4% | 19.7% | 2012 | 29.4% | $154,583 |
| Fresno | 119,498 | 3.1% | 4.9% | 13.9% | 22.0% | 38.8% | 17.4% | 2011 | 34.7% | $199,367 |
| San Joaquin | 634 | 2.5% | 4.5% | 20.5% | 28.1% | 36.8% | 7.6% | 2007 | 28.7% | $114,957 |
| Clovis | 34,732 | 2.1% | 3.8% | 10.1% | 21.2% | 39.3% | 23.5% | 2014 | 38.5% | $315,353 |
| Sacramento County — 8 cities and communities; year = Date the current enrolled value was set (VALUE_DT); 1975 marks the original Prop 13 base; exemption column = Homeowners' Exemption amount > 0; Assessor extract of 2026-08-29; confidence medium. | ||||||||||
| Isleton | 225 | 8.0% | 6.2% | 8.0% | 13.8% | 37.3% | 26.7% | 2015 | 33.8% | $215,547 |
| Citrus Heights | 22,457 | 5.3% | 7.6% | 9.9% | 16.8% | 30.6% | 29.8% | 2014 | 47.9% | $303,632 |
| Sacramento | 128,389 | 5.2% | 5.8% | 8.7% | 18.3% | 33.0% | 29.0% | 2014 | 44.8% | $329,964 |
| Unincorporated (unincorporated) | 153,471 | 4.9% | 5.8% | 10.1% | 17.9% | 31.6% | 29.6% | 2014 | 48.7% | $340,781 |
| Rancho Cordova | 22,282 | 3.8% | 3.9% | 4.8% | 13.5% | 31.3% | 42.8% | 2018 | 43.5% | $408,000 |
| Galt | 7,788 | 1.4% | 2.3% | 11.6% | 18.6% | 29.9% | 36.1% | 2016 | 45.5% | $358,768 |
| Elk Grove | 54,242 | 0.7% | 2.0% | 8.2% | 23.8% | 36.0% | 29.3% | 2014 | 48.7% | $456,245 |
| Folsom | 26,297 | 0.6% | 2.6% | 9.3% | 19.7% | 30.2% | 37.5% | 2016 | 52.2% | $593,315 |
Counties where the year is the last recorded sale or document
These counties publish no base-year field. The year is that of the last recorded sale (San Francisco) or the last recorded document of any kind (San Diego, Alameda) or of the current recorded deed (Contra Costa). A deed between spouses or into a trust resets that date without resetting the Proposition 13 base, so these shares understate lock-in and are not comparable with the table above. San Francisco's source starts in 1983, so its pre-1980 cell is blank and a quarter of its parcels have no date; San Diego's last column is the Assessor's owner-occupied indicator, not the exemption.
| City | Homes | Pre-1980 | 1980s | 1990s | 2000s | 2010s | 2020+ | Median sale / document year | Exemption / owner-occupied share | Median taxable value |
|---|---|---|---|---|---|---|---|---|---|---|
| San Francisco County — 1 city; year = Year of the most recent recorded sale (current_sales_date); the source starts in 1983, so there is no pre-1980 bin and about a quarter of parcels have no date; exemption column = Homeowners' Exemption value > 0; 2025 roll (series back to 2007); confidence medium. | ||||||||||
| San Francisco | 155,111 | — | 4.4% | 18.0% | 22.7% | 33.0% | 21.9% | 2011 | 47.5% | $767,479 |
| San Diego County — 19 cities and communities; year = Year of the latest recorded document of any kind (DOCDATE), not a base year; exemption column = Owner-occupied indicator (OWNEROCC), not the exemption; layer read 2026-10-24; confidence low. | ||||||||||
| Imperial Beach | 4,312 | 0.9% | 0.8% | 4.0% | 11.1% | 32.7% | 50.6% | 2020 | 43.3% | $466,389 |
| National City | 6,645 | 0.7% | 1.5% | 4.5% | 17.5% | 31.1% | 44.6% | 2018 | 53.8% | $290,189 |
| Santee | 15,683 | 0.4% | 1.1% | 4.1% | 12.5% | 31.9% | 50.0% | 2019 | 60.3% | $465,317 |
| Lemon Grove | 5,614 | 0.4% | 1.3% | 4.7% | 14.3% | 31.2% | 48.1% | 2019 | 57.0% | $387,275 |
| Del Mar | 1,716 | 0.4% | 0.6% | 6.2% | 12.7% | 33.2% | 47.0% | 2019 | 43.1% | $1,677,880 |
| Coronado | 6,750 | 0.3% | 1.5% | 4.0% | 12.3% | 34.2% | 47.7% | 2019 | 38.0% | $1,226,305 |
| La Mesa | 14,284 | 0.3% | 0.9% | 4.2% | 12.8% | 34.6% | 47.2% | 2019 | 58.1% | $435,655 |
| San Diego | 325,023 | 0.3% | 1.0% | 4.1% | 13.6% | 34.2% | 46.8% | 2019 | 58.1% | $524,435 |
| Unincorporated (unincorporated) | 125,313 | 0.2% | 0.9% | 3.5% | 12.3% | 32.0% | 51.2% | 2020 | 59.0% | $560,000 |
| El Cajon | 17,336 | 0.2% | 0.8% | 3.5% | 13.7% | 33.1% | 48.7% | 2019 | 52.0% | $414,073 |
| Encinitas | 19,050 | 0.2% | 0.9% | 3.9% | 13.7% | 35.0% | 46.4% | 2019 | 62.0% | $800,997 |
| Poway | 13,651 | 0.2% | 0.9% | 4.0% | 13.3% | 33.6% | 47.9% | 2019 | 69.3% | $690,540 |
| Solana Beach | 5,106 | 0.2% | 0.9% | 4.1% | 13.3% | 35.9% | 45.6% | 2019 | 53.3% | $930,821 |
| Chula Vista | 59,508 | 0.2% | 0.7% | 3.1% | 14.0% | 34.6% | 47.4% | 2019 | 56.4% | $513,167 |
| Oceanside | 49,904 | 0.2% | 0.9% | 3.5% | 12.7% | 33.3% | 49.5% | 2019 | 53.4% | $467,404 |
| Escondido | 29,835 | 0.1% | 0.7% | 3.6% | 13.7% | 32.5% | 49.4% | 2019 | 56.3% | $477,881 |
| Vista | 18,868 | 0.1% | 0.7% | 3.7% | 13.3% | 32.6% | 49.5% | 2019 | 57.9% | $484,207 |
| San Marcos | 22,403 | 0.1% | 0.4% | 2.5% | 12.1% | 33.7% | 51.2% | 2020 | 56.6% | $586,088 |
| Carlsbad | 36,833 | 0.1% | 0.5% | 2.6% | 12.0% | 35.6% | 49.2% | 2019 | 61.2% | $772,852 |
| Alameda County — 15 cities and communities; year = Latest recorded document date of any kind (LatestDocumentDate); exemption column = Homeowners' Exemption amount > 0; layer read 2026-10-24; confidence low-medium. | ||||||||||
| Oakland | 79,481 | 0.9% | 1.7% | 5.1% | 14.9% | 32.2% | 45.3% | 2019 | 58.8% | $481,515 |
| Union City | 16,613 | 0.8% | 1.5% | 6.1% | 17.3% | 35.6% | 38.8% | 2017 | 58.9% | $558,027 |
| Newark | 15,067 | 0.7% | 1.3% | 5.1% | 13.4% | 31.9% | 47.5% | 2019 | 55.3% | $635,723 |
| Berkeley | 19,144 | 0.7% | 1.5% | 5.8% | 14.8% | 33.1% | 44.1% | 2018 | 71.4% | $682,959 |
| Hayward | 31,215 | 0.7% | 1.3% | 4.9% | 15.4% | 34.9% | 42.7% | 2018 | 54.2% | $514,023 |
| San Leandro | 20,742 | 0.7% | 1.3% | 6.4% | 17.6% | 33.9% | 40.3% | 2017 | 62.2% | $480,846 |
| Albany | 4,693 | 0.6% | 1.7% | 5.9% | 14.9% | 35.7% | 41.2% | 2017 | 66.1% | $531,035 |
| Unincorporated (unincorporated) | 34,142 | 0.5% | 1.3% | 5.5% | 16.4% | 33.5% | 42.8% | 2018 | 61.8% | $550,890 |
| Livermore | 26,453 | 0.4% | 0.9% | 4.3% | 12.4% | 33.4% | 48.6% | 2019 | 60.1% | $717,709 |
| Fremont | 76,134 | 0.4% | 1.3% | 9.8% | 13.3% | 33.6% | 41.6% | 2017 | 51.9% | $632,942 |
| Alameda | 16,888 | 0.4% | 1.5% | 5.2% | 14.9% | 32.1% | 46.0% | 2019 | 67.9% | $696,629 |
| Emeryville | 3,753 | 0.3% | 1.3% | 4.5% | 15.5% | 38.5% | 40.0% | 2017 | 40.4% | $403,448 |
| Pleasanton | 22,057 | 0.3% | 0.7% | 4.0% | 15.5% | 34.3% | 45.3% | 2019 | 63.5% | $921,160 |
| Dublin | 20,504 | 0.1% | 2.2% | 3.3% | 9.2% | 37.3% | 47.9% | 2019 | 52.7% | $950,000 |
| Piedmont | 3,741 | 0.1% | 1.0% | 4.8% | 14.4% | 35.0% | 44.7% | 2018 | 72.4% | $1,379,871 |
| Contra Costa County — 20 cities and communities; year = Year of the current recorded deed (C_DED_DateStr; no county definition, but it matches the recorder document number's year in 98% of 1994+ rows and runs to August 2026, so it is a deed date, not a base year); exemption column = Exemption code HO; live layer read 2026-10-24, carrying 2026-27 roll values; confidence low-medium. | ||||||||||
| Richmond | 26,740 | 1.1% | 2.0% | 5.8% | 17.3% | 35.2% | 38.7% | 2017 | 44.7% | $381,816 |
| San Pablo | 5,717 | 0.9% | 2.8% | 6.7% | 20.9% | 34.9% | 33.9% | 2016 | 39.9% | $274,323 |
| Pinole | 5,990 | 0.8% | 2.4% | 6.8% | 17.4% | 34.8% | 37.8% | 2017 | 51.9% | $414,348 |
| El Cerrito | 7,578 | 0.7% | 1.8% | 6.4% | 16.2% | 34.0% | 40.8% | 2017 | 55.3% | $638,072 |
| Concord | 35,285 | 0.7% | 1.6% | 5.5% | 15.8% | 34.3% | 42.1% | 2018 | 45.4% | $429,202 |
| Pittsburg | 18,314 | 0.7% | 1.8% | 4.5% | 16.9% | 37.0% | 39.1% | 2017 | 38.8% | $388,788 |
| Unincorporated (unincorporated) | 53,201 | 0.5% | 1.3% | 5.3% | 15.6% | 35.6% | 41.7% | 2018 | 46.4% | $583,663 |
| Martinez | 12,074 | 0.5% | 1.7% | 5.5% | 15.1% | 34.8% | 42.5% | 2018 | 53.8% | $503,595 |
| Hercules | 8,392 | 0.5% | 2.8% | 5.6% | 18.6% | 34.8% | 37.7% | 2017 | 51.3% | $473,534 |
| Antioch | 32,543 | 0.5% | 1.1% | 4.2% | 15.0% | 34.8% | 44.5% | 2018 | 37.2% | $425,519 |
| Pleasant Hill | 10,706 | 0.5% | 1.5% | 5.2% | 15.0% | 35.4% | 42.5% | 2018 | 53.3% | $607,049 |
| Orinda | 7,007 | 0.4% | 0.9% | 5.1% | 14.7% | 34.9% | 43.9% | 2018 | 58.2% | $1,338,111 |
| Walnut Creek | 26,269 | 0.4% | 0.9% | 4.1% | 13.3% | 36.7% | 44.5% | 2018 | 55.4% | $585,243 |
| Lafayette | 8,168 | 0.4% | 1.3% | 5.7% | 16.1% | 36.7% | 39.8% | 2017 | 56.9% | $1,174,939 |
| Clayton | 4,056 | 0.4% | 1.1% | 5.7% | 15.3% | 35.9% | 41.5% | 2018 | 59.6% | $725,549 |
| Moraga | 5,473 | 0.2% | 1.0% | 6.0% | 15.1% | 35.9% | 41.8% | 2018 | 58.2% | $957,376 |
| Danville | 15,502 | 0.2% | 0.8% | 4.8% | 14.2% | 36.8% | 43.1% | 2018 | 56.4% | $1,031,551 |
| San Ramon | 24,964 | 0.2% | 0.7% | 4.7% | 14.1% | 39.2% | 41.2% | 2018 | 49.5% | $988,027 |
| Brentwood | 20,689 | 0.1% | 0.3% | 2.1% | 12.5% | 36.9% | 48.2% | 2019 | 46.2% | $622,397 |
| Oakley | 13,522 | 0.1% | 1.1% | 3.2% | 13.7% | 34.4% | 47.5% | 2019 | 39.6% | $512,583 |
San Francisco, 2007 to 2025
DataSF's historical rolls let the same measure be followed for one city: the share of homes whose last sale is in each decade, the median sale year, the exemption share and the median net taxable value.
| Roll year | Homes | Dated | 1980s | 1990s | 2000s | 2010s | 2020+ | Median sale year | Exemption share | Median taxable value |
|---|---|---|---|---|---|---|---|---|---|---|
| 2007 | 135,290 | 78,146 | 8.5% | 36.7% | 54.7% | 0.0% | 0.0% | 2001 | 57.4% | $311,703 |
| 2010 | 140,517 | 85,626 | 7.5% | 31.6% | 56.5% | 4.4% | 0.0% | 2002 | 57.1% | $363,067 |
| 2013 | 143,708 | 93,253 | 6.5% | 27.0% | 42.8% | 23.7% | 0.0% | 2004 | 55.8% | $417,000 |
| 2016 | 147,882 | 99,794 | 5.8% | 23.8% | 34.1% | 36.3% | 0.0% | 2006 | 54.0% | $493,506 |
| 2019 | 151,721 | 106,904 | 5.1% | 21.0% | 28.4% | 45.4% | 0.0% | 2008 | 50.5% | $592,856 |
| 2022 | 153,731 | 110,611 | 4.8% | 19.5% | 25.3% | 38.7% | 11.6% | 2010 | 47.5% | $684,677 |
| 2025 | 155,111 | 114,894 | 4.4% | 18.0% | 22.7% | 33.0% | 21.9% | 2011 | 47.5% | $767,479 |
Riverside County, 2004–05 to 2026–27: the lock-in eroding
The Riverside County Assessor publishes “Assessed Value by Base Year” every year for the whole secured roll (all property types). It is the longest public base-year series in California. Parcels still on the 1975 base fall every year as they change hands, and the pre-2000 share of assessed value has shrunk from 43% to 6%.
| Tax year | Assessments | Still on a 1975 base | Share of assessments | Share of assessed value | Pre-2000 base: share of assessments | Pre-2000 base: share of assessed value |
|---|---|---|---|---|---|---|
| 2004-2005 | 777,670 | 53,096 | 6.8% | 2.1% | 52.7% | 43.0% |
| 2005-2006 | 810,464 | 50,106 | 6.2% | 1.7% | 45.7% | 33.6% |
| 2006-2007 | 852,817 | 44,464 | 5.2% | 1.3% | 39.4% | 25.6% |
| 2007-2008 | 877,545 | 41,074 | 4.7% | 1.1% | 35.7% | 21.1% |
| 2008-2009 | 895,405 | 40,038 | 4.5% | 1.1% | 33.9% | 20.5% |
| 2009-2010 | 901,189 | 38,580 | 4.3% | 1.2% | 32.6% | 22.7% |
| 2010-2011 | 903,743 | 37,803 | 4.2% | 1.2% | 31.6% | 22.8% |
| 2011-2012 | 904,040 | 36,593 | 4.0% | 1.2% | 30.4% | 22.3% |
| 2013-2014 | 906,467 | 33,916 | 3.7% | 1.1% | 27.8% | 20.4% |
| 2014-2015 | 909,432 | 32,325 | 3.5% | 1.0% | 26.5% | 18.3% |
| 2015-2016 | 914,886 | 30,785 | 3.4% | 0.9% | 25.1% | 16.9% |
| 2016-2017 | 919,810 | 29,403 | 3.2% | 0.9% | 23.9% | 15.6% |
| 2017-2018 | 925,405 | 27,918 | 3.0% | 0.8% | 22.6% | 14.4% |
| 2018-2019 | 931,922 | 26,549 | 2.9% | 0.7% | 21.4% | 13.2% |
| 2019-2020 | 934,810 | 24,100 | 2.6% | 0.6% | 19.8% | 11.7% |
| 2020-2021 | 935,096 | 23,080 | 2.5% | 0.6% | 18.9% | 10.9% |
| 2021-2022 | 940,948 | 21,947 | 2.3% | 0.5% | 17.9% | 9.9% |
| 2022-2023 | 946,302 | 20,296 | 2.1% | 0.5% | 16.7% | 8.7% |
| 2023-2024 | 954,522 | 18,796 | 2.0% | 0.4% | 15.6% | 7.7% |
| 2024-2025 | 962,542 | 17,457 | 1.8% | 0.4% | 14.6% | 7.0% |
| 2025-2026 | 968,364 | 16,355 | 1.7% | 0.3% | 13.8% | 6.5% |
| 2026-2027 | 973,455 | 15,282 | 1.6% | 0.3% | 13.1% | 6.1% |
The report prints its first row as “1975”, not “1975 and prior”. The 2012–13 report is an image-only PDF and is not in the series.
Santa Clara County: the Assessor's own base-year table
Santa Clara publishes no parcel field, but its 2025 Annual Report prints the secured roll by base-year band, by property type and by city. For single-family homes and condos countywide: 8% of parcels carry a base year before 1979, 8% 1979–1988, 13% 1989–1998, 20% 1999–2008, 27% 2009–2018 and 24% 2019 or later. By city (all secured property, share of parcels; the report's own bands, so not comparable with the tables above):
| City | Before 1979 | 1979–1988 | 1989–1998 | 1999–2008 | 2009–2018 | 2019 to date | Before 1979, share of assessed value |
|---|---|---|---|---|---|---|---|
| Palo Alto | 12% | 10% | 14% | 20% | 24% | 21% | 9% |
| Unincorporated | 12% | 10% | 12% | 18% | 26% | 23% | 20% |
| Los Altos | 11% | 9% | 14% | 19% | 25% | 21% | 1% |
| Los Altos Hills | 11% | 11% | 15% | 18% | 25% | 20% | 1% |
| Monte Sereno | 11% | 9% | 14% | 17% | 21% | 28% | 1% |
| Santa Clara | 11% | 8% | 10% | 19% | 26% | 26% | 3% |
| Saratoga | 11% | 9% | 16% | 19% | 24% | 21% | 2% |
| Mountain View | 10% | 7% | 11% | 20% | 27% | 26% | 1% |
| Sunnyvale | 10% | 8% | 12% | 19% | 26% | 25% | 2% |
| Campbell | 9% | 9% | 13% | 19% | 26% | 25% | 1% |
| Los Gatos | 9% | 9% | 12% | 16% | 25% | 29% | 2% |
| Cupertino | 8% | 10% | 16% | 25% | 23% | 18% | 1% |
| Milpitas | 8% | 8% | 13% | 18% | 28% | 26% | 5% |
| San Jose | 8% | 9% | 13% | 20% | 27% | 23% | 2% |
| Gilroy | 5% | 6% | 8% | 17% | 33% | 31% | 1% |
| Morgan Hill | 4% | 5% | 10% | 18% | 28% | 35% | 1% |
Homeowners' Exemption claims by county, 2000–01 to 2025–26
The Board of Equalization counts Homeowners' Exemptions on every county's roll (Annual Report Table 9). Divided by the Census Bureau's owner-occupied housing units (ACS 2020–2024 five-year, table B25003), that gives claims per 100 owner-occupied homes: a coverage ratio, not an eligibility rate, because the two sources count homes differently and not every eligible owner files the one-time claim. Statewide: 5,207,251 claims in 2000–01, 4,715,414 in 2023–24, 4,683,154 in 2024–25 and 4,636,214 in 2025–26, against 7,567,568 owner-occupied homes. Los Angeles County: 917,549 claims, 58.52 per 100.
| County | Claims 2025–26 | Claims 2000–01 | Change | Owner-occupied homes (ACS 2020–24) | Claims per 100 owner-occupied, 2025–26 |
|---|---|---|---|---|---|
| Modoc | 1,954 | 2,339 | -16.5% | 2,530 | 77.2 |
| Sierra | 668 | 855 | -21.9% | 879 | 76.0 |
| Alameda | 238,221 | 241,657 | -1.4% | 325,509 | 73.2 |
| San Mateo | 112,787 | 138,958 | -18.8% | 154,607 | 73.0 |
| Marin | 48,496 | 55,622 | -12.8% | 66,616 | 72.8 |
| Colusa | 3,367 | 3,365 | +0.1% | 4,674 | 72.0 |
| Nevada | 23,249 | 22,980 | +1.2% | 32,342 | 71.9 |
| Shasta | 33,493 | 36,150 | -7.3% | 46,694 | 71.7 |
| San Diego | 455,841 | 461,474 | -1.2% | 639,138 | 71.3 |
| Ventura | 128,612 | 131,475 | -2.2% | 181,039 | 71.0 |
| San Luis Obispo | 47,370 | 45,379 | +4.4% | 67,986 | 69.7 |
| Tehama | 11,530 | 12,682 | -9.1% | 16,640 | 69.3 |
| Glenn | 4,124 | 4,796 | -14.0% | 6,002 | 68.7 |
| Humboldt | 21,325 | 25,197 | -15.4% | 31,053 | 68.7 |
| Siskiyou | 9,004 | 10,732 | -16.1% | 13,203 | 68.2 |
| Santa Cruz | 39,458 | 42,215 | -6.5% | 58,079 | 67.9 |
| Lassen | 4,254 | 5,684 | -25.2% | 6,305 | 67.5 |
| Yolo | 27,601 | 26,606 | +3.7% | 41,637 | 66.3 |
| Placer | 78,127 | 57,464 | +36.0% | 118,103 | 66.2 |
| El Dorado | 38,826 | 35,487 | +9.4% | 58,844 | 66.0 |
| Santa Clara | 237,238 | 287,248 | -17.4% | 363,147 | 65.3 |
| Napa | 20,549 | 22,576 | -9.0% | 31,555 | 65.1 |
| Santa Barbara | 50,989 | 63,249 | -19.4% | 78,344 | 65.1 |
| Amador | 8,280 | 7,517 | +10.2% | 12,941 | 64.0 |
| Orange | 390,153 | 460,517 | -15.3% | 610,659 | 63.9 |
| Butte | 30,475 | 40,712 | -25.1% | 47,717 | 63.9 |
| Sutter | 12,930 | 14,303 | -9.6% | 20,417 | 63.3 |
| San Benito | 8,843 | 8,759 | +1.0% | 13,970 | 63.3 |
| Tuolumne | 10,584 | 12,439 | -14.9% | 16,771 | 63.1 |
| Merced | 29,037 | 29,998 | -3.2% | 46,474 | 62.5 |
| Stanislaus | 67,942 | 75,431 | -9.9% | 108,828 | 62.4 |
| Mariposa | 3,496 | 4,142 | -15.6% | 5,611 | 62.3 |
| Calaveras | 9,542 | 9,831 | -2.9% | 15,480 | 61.6 |
| Sacramento | 206,900 | 222,529 | -7.0% | 337,066 | 61.4 |
| Plumas | 3,683 | 5,495 | -33.0% | 6,006 | 61.3 |
| Monterey | 41,070 | 51,339 | -20.0% | 68,993 | 59.5 |
| San Francisco | 82,436 | 94,930 | -13.2% | 139,057 | 59.3 |
| Yuba | 10,763 | 8,982 | +19.8% | 18,182 | 59.2 |
| Sonoma | 70,295 | 89,855 | -21.8% | 119,598 | 58.8 |
| Contra Costa | 165,529 | 214,468 | -22.8% | 281,819 | 58.7 |
| Alpine | 199 | 181 | +9.9% | 340 | 58.5 |
| Los Angeles | 917,549 | 1,153,373 | -20.4% | 1,567,983 | 58.5 |
| Del Norte | 3,888 | 4,913 | -20.9% | 6,673 | 58.3 |
| Inyo | 3,052 | 3,948 | -22.7% | 5,339 | 57.2 |
| San Joaquin | 86,122 | 89,293 | -3.5% | 152,030 | 56.6 |
| Trinity | 2,261 | 3,084 | -26.7% | 4,006 | 56.4 |
| Kings | 13,428 | 16,105 | -16.6% | 23,870 | 56.3 |
| Solano | 54,495 | 60,313 | -9.7% | 99,263 | 54.9 |
| Kern | 93,315 | 100,043 | -6.7% | 171,133 | 54.5 |
| Mendocino | 11,608 | 15,877 | -26.9% | 21,500 | 54.0 |
| Madera | 16,334 | 16,880 | -3.2% | 30,613 | 53.4 |
| San Bernardino | 222,094 | 226,661 | -2.0% | 418,836 | 53.0 |
| Imperial | 14,751 | 16,983 | -13.1% | 28,210 | 52.3 |
| Riverside | 274,102 | 233,230 | +17.5% | 535,986 | 51.1 |
| Lake | 9,446 | 12,590 | -25.0% | 19,441 | 48.6 |
| Fresno | 84,741 | 113,616 | -25.4% | 180,371 | 47.0 |
| Mono | 1,729 | 2,160 | -20.0% | 3,758 | 46.0 |
| Tulare | 38,059 | 52,564 | -27.6% | 83,701 | 45.5 |
Owner-occupied units carry a margin of error (shown in the CSV). The 2000–01 count is a level reference only: no ratio is published for it, because the only denominator is today's. The BOE's exempt value divided by its claim count comes to a little over the statutory $7,000 in 30 of the 232 county-years on the unrounded figures (29 in the rounded public CSV; Plumas 2023–24 highest, $7,589); the BOE does not explain it, so the download prints the value as published beside the per-claim figure rather than correcting either. The exemption's rules are on the Homeowners' Exemption guide; the main calculator can now subtract it.
Frequently Asked Questions
What does "Prop 13 lock-in" mean?
Under Proposition 13 a home's taxable value is set when it changes hands (its base year) and can then rise at most 2% a year, however much the market rises. A home that has not changed hands since 1975 is taxed on its 1975 roll value grown 2% a year; a home bought in 1978 is taxed on its 1978 price grown the same way; the neighbour that sold last year is taxed on last year's price. The longer a city's homes have gone without a sale, the more "locked in" its tax base is: the share of homes carrying a pre-1980 base year is the cleanest single measure, because every one of them was last reassessed at the 1975 value Proposition 13 rolled back to.
Why do you say 1975 when the home sold in 1978?
Proposition 13 (June 1978) set every property's base value at its March 1, 1975 assessed value, or its value at the first sale or new construction after that. Assessors record that as a 1975 base year. A home bought in 1976 or 1977 was simply reassessed at purchase and also shows a 1970s base year. So the "pre-1980" share here is the share of homes taxed on a 1970s value.
Where does the base year come from, and why is it a proxy in some counties?
Only Los Angeles, San Bernardino and Fresno publish a field called base year on their parcel data, and Sacramento publishes the date the current value was set, which behaves the same way. San Francisco, San Diego, Alameda and Contra Costa publish only the date of the last recorded sale or document, which this page uses as a proxy and labels as such: a quitclaim between spouses or a refinance deed resets the proxy without resetting the Proposition 13 base, so the proxy understates lock-in. Ventura is left out because its only date field has no published meaning. The method table on this page states the field for every county.
What does the Homeowners' Exemption share tell me?
The $7,000 Homeowners' Exemption can be claimed only on an owner-occupied principal residence, so the share of homes claiming it is a proxy for owner-occupancy (it runs low because not every eligible owner files). San Diego's column is the Assessor's owner-occupied indicator rather than the exemption. By county, the Board of Equalization's annual counts are divided by Census ACS owner-occupied housing units to give claims per 100 owner-occupied homes; that is a coverage ratio, not a take-up rate, because the two sources count homes differently.
Why did statewide Homeowners' Exemption claims fall from 5,207,251 to 4,636,214?
The Board of Equalization's Table 9 shows 5,207,251 claims in 2000–01 and 4,636,214 in 2025–26, 11% fewer, over a period when the stock of owner-occupied homes grew. The BOE publishes the counts, not the reason; the series is reproduced here so the trend can be seen county by county. No claims-per-100 ratio is published for 2000–01, because the only denominator available is today's; that year's count is a level reference only.
Is this parcel-level data? Can I look up my own home?
No. Every figure is a city or county aggregate built from public assessor data, and any cell built from fewer than 30 homes is suppressed. Your own base year is on your tax bill and in your assessor's parcel lookup. To estimate what a long-held home pays today, use the Proposition 13 calculator with its original purchase year.
Why is Riverside's series the whole roll, not homes?
The Riverside County Assessor's "Assessed Value by Base Year" report covers every secured parcel: homes, apartments, commercial and land. It is still the longest public base-year series in California (2004–05 to 2026–27), so it is shown as published, with that caveat.
Primary sources: California Constitution, article XIII A (Proposition 13) · Revenue and Taxation Code §51 (the 2% cap) · Revenue and Taxation Code §218 (Homeowners' Exemption) · California State Board of Equalization Annual Report, Table 9 (Homeowners' Exemptions by county) · US Census ACS 5-year 2020–2024. Check a figure against the document before relying on it. Last reviewed October 2026.
Learn More
Sources: County assessor parcel layers and open-data rolls (Los Angeles 2025 roll; San Francisco DataSF; Sacramento, San Diego, Alameda, Contra Costa, San Bernardino, Fresno ArcGIS layers, read 2026-10-24), the BOE Annual Report Table 9 (Homeowners' Exemptions by county) with the ACS 2020–2024 owner-occupied denominator, the Riverside County Assessor's Assessed Value by Base Year reports 2004–05 to 2026–27, and the Santa Clara County Assessor's 2025 Annual Report. City-level aggregates only; no parcel, address or owner data. Cells built from fewer than 30 parcels are suppressed. Where a county publishes no base-year field, the year of the last recorded sale or document is used and labelled as a proxy. Riverside: Riverside County Assessor, Assessed Value by Base Year, 2026/2027 Tax Year and the earlier reports in the same series at rivcoacr.org. Santa Clara: Santa Clara County Assessor, Annual Report 2025 (roll 2025–26), pages 20, 21 and 50. Statewide exemption counts: Board of Equalization open data (Gross Assessed Values and Homeowners' Exemptions); denominator: U.S. Census Bureau ACS 2020–2024 five-year estimates, table B25003. Downloads: cities (CSV) and exemptions by county (CSV). Educational information, not legal or tax advice.
Data assembled October 2026.