The 50 Most Expensive Counties in America (2026)

Q: What is the most expensive county in the United States?

San Mateo County, California is the most expensive county in the United States, with a typical home value of $1,581,000. Santa Clara County, California ($1,567,000) and Marin County, California ($1,465,000) come next. Figures are Zillow's typical home values for August 2026 and cover counties with 50,000 or more residents.

The Million-Dollar Club

San Mateo County, California tops the list, where a typical home is worth $1,581,000. It has plenty of company: 10 of the 50 counties have a typical home value above $1 million, and California (17), New York (8), Massachusetts (5) hold 30 of the 50 spots between them.

What a Local Paycheck Is Up Against

A high price is easier to carry where incomes are high too, and that varies a lot. In Eagle County, Colorado, the typical home costs about 12.5 times the typical household income. In Loudoun County, Virginia, it is 4.4 times.

Expensive Is Not the Same as Climbing

Being at the top does not mean prices keep running. Over the past year, 9 of these 50 counties saw typical values slip. San Francisco County, California went the other way, up 13.7%.

#	County	BTI Score	Typical Home Value	Price Change (1 yr)	Med. Income	Population
01	San Mateo County CA	11	$1,581,355	+3.5%	$158,855	742,340
02	Santa Clara County CA	2	$1,566,638	+0.3%	$164,281	1,902,047
03	Marin County CA	95	$1,464,630	+4.3%	$149,091	257,969
04	San Francisco County CA	11	$1,424,486	+13.7%	$140,970	830,235
05	Eagle County CO	92	$1,302,808	+2.9%	$104,096	55,135
06	New York County NY	65	$1,223,135	+3.0%	$103,931	1,629,477
07	Orange County CA	43	$1,178,889	+2.8%	$116,289	3,165,820
08	Santa Cruz County CA	82	$1,148,774	+4.6%	$111,093	264,926
09	Alameda County CA	47	$1,048,143	-1.1%	$129,367	1,649,473
10	Kauai County HI	58	$1,018,601	+2.0%	$97,668	73,731
11	Santa Barbara County CA	2	$991,951	+4.0%	$98,161	443,701
12	Maui County HI	32	$987,614	-3.3%	$97,161	164,522
13	Monroe County FL	92	$959,844	+1.1%	$87,738	81,860
14	Kings County NY	62	$959,075	+5.0%	$80,263	2,631,580
15	San Diego County CA	9	$930,800	+0.5%	$106,268	3,288,774
16	Williamson County TN	60	$929,377	+2.4%	$135,594	260,351
17	San Luis Obispo County CA	20	$897,783	+1.8%	$97,446	281,555
18	Westchester County NY	86	$884,652	+7.2%	$118,976	999,677
19	Los Angeles County CA	9	$873,008	+0.5%	$90,112	9,808,667
20	Ventura County CA	6	$871,724	+0.8%	$109,797	837,469
21	Napa County CA	8	$871,204	-1.7%	$111,471	134,869
22	Nassau County NY	70	$856,988	+5.5%	$146,202	1,389,591
23	Honolulu County HI	41	$856,332	+2.3%	$106,195	1,001,146
24	Monterey County CA	68	$843,096	+0.9%	$97,230	437,613
25	King County WA	9	$835,385	-2.0%	$124,746	2,287,171
26	Middlesex County MA	24	$814,047	+1.6%	$130,847	1,638,365
27	Arlington County VA	4	$806,890	+0.8%	$142,114	236,254
28	Cape May County NJ	94	$806,250	+9.3%	$91,128	94,941
29	Loudoun County VA	10	$795,391	+1.4%	$181,765	432,998
30	Monmouth County NJ	79	$793,713	+6.5%	$124,845	645,353
31	Newport County RI	97	$790,998	+5.7%	$103,514	84,657
32	Bergen County NJ	65	$786,765	+6.9%	$124,884	962,316
33	Sonoma County CA	38	$785,115	+0.0%	$104,674	485,040
34	Norfolk County MA	29	$773,309	+2.3%	$130,739	730,082
35	Contra Costa County CA	54	$771,709	-1.1%	$127,229	1,165,012
36	San Benito County CA	73	$766,958	-0.5%	$114,394	67,290
37	Rockland County NY	87	$766,355	+4.9%	$109,959	341,883
38	Barnstable County MA	55	$762,440	+2.4%	$95,241	231,668
39	Fairfax County VA	4	$760,599	+0.8%	$153,637	1,147,837
40	Suffolk County MA	10	$750,961	+0.4%	$95,631	785,121
41	Queens County NY	25	$744,565	+4.7%	$86,136	2,323,052
42	Suffolk County NY	85	$738,423	+3.7%	$130,686	1,530,146
43	Snohomish County WA	15	$734,626	-1.7%	$111,246	844,430
44	Richmond County NY	35	$728,958	+5.4%	$98,333	494,956
45	Essex County MA	43	$722,540	+2.1%	$101,883	813,054
46	Boulder County CO	15	$712,033	-0.8%	$103,994	328,961
47	Garfield County CO	96	$711,349	+3.6%	$91,131	62,479
48	Morris County NJ	46	$709,718	+4.0%	$137,326	514,528
49	Gallatin County MT	30	$700,687	+0.7%	$93,528	124,074
50	Douglas County CO	5	$698,897	-1.6%	$149,594	377,150

Frequently Asked Questions

What is the most expensive county in the United States?

San Mateo County, California is the most expensive county in the United States, with a typical home value of $1,581,000. Santa Clara County, California ($1,567,000) and Marin County, California ($1,465,000) come next. Figures are Zillow's typical home values for August 2026 and cover counties with 50,000 or more residents.

Which states have the most expensive counties?

Of the 50 most expensive counties, California leads with 17, followed by New York (8) and Massachusetts (5). The 50 counties are spread across 12 states.

How is the most-expensive-counties ranking calculated?

Counties are ranked by the Zillow Home Value Index for August 2026: the typical value of single-family homes and condos in the middle third of the local market, smoothed and seasonally adjusted. Median household income is from the Census Bureau's American Community Survey. Counties with fewer than 50,000 residents are not ranked.

Are home prices still rising in the most expensive counties?

Mostly, but not everywhere. Of the 50, 9 saw typical home values fall over the past year. The biggest rise was in San Francisco County, California (+13.7%) and the biggest fall in Maui County, Hawaii (-3.3%).

Most Expensive Counties in America