Which ZIP code in San Mateo County has the highest median age?

94028 (Portola Valley), at 57.2 (±5.8), among 28 ZIP codes with at least 1,000 residents.

Why are some ZIP codes missing?

ZIP codes with fewer than 1,000 residents are left out because their survey estimates swing too much to rank, and so are ZIP codes where the Census Bureau did not publish this figure.

Oldest ZIP codes in San Mateo County, CA

These are the 25 ZIP codes in San Mateo County with the highest median age, out of 28 with at least 1,000 residents. 94028 (Portola Valley, 57.2), 94018 (El Granada, 51.4) and 94037 (Montara, 50.5) lead the list. There is no single "best" ZIP code in San Mateo County; the right one depends on who you want to reach, so the same ZIP codes are ranked several ways below.

Oldest ZIP codes in San Mateo County

Rank	ZIP	Mailing city	Median age	Residents	Households	Residential mailboxes
1	94028	Portola Valley	57.2 ±5.8	6,531	2,637	2,612
2	94018	El Granada	51.4 ±4.5	3,834	1,563	—
3	94037	Montara	50.5 ±12.8	2,917	1,003	—
4	94027	Atherton	49.1 ±2.7	7,002	2,236	2,478
5	94038	Moss Beach	47.1 ±11.7	2,683	915	797
6	94019	Half Moon Bay	46.9 ±3.2	14,419	5,221	5,940
7	94020	La Honda	46.8 ±14.4	1,694	829	198
8	94044	Pacifica	44.6 ±1.4	37,274	13,928	—
9	94062	Redwood City	44.0 ±2.0	25,759	9,729	10,388
10	94030	Millbrae	43.7 ±1.8	22,689	8,121	9,065
11	94005	Brisbane	43.6 ±3.4	4,692	1,912	2,005
12	94080	South San Francisco	43.1 ±1.4	64,761	21,966	22,939
13	94065	Redwood City	43.0 ±1.7	11,673	4,569	5,233
14	94014	Daly City	42.9 ±1.7	45,315	14,101	14,348
15	94010	Burlingame	42.5 ±1.0	43,025	16,317	18,939
16	94015	Daly City	41.6 ±1.2	64,091	20,350	20,600
17	94070	San Carlos	41.6 ±1.6	30,447	11,279	12,601
18	94060	Pescadero	41.3 ±11.0	1,465	362	—
19	94402	San Mateo	40.8 ±1.5	25,475	10,125	10,696
20	94404	San Mateo	39.8 ±1.4	35,881	14,717	15,551
21	94002	Belmont	39.8 ±1.2	27,534	10,567	11,615
22	94066	San Bruno	39.7 ±1.1	42,728	15,224	16,434
23	94025	Menlo Park	39.6 ±1.3	40,721	14,619	18,110
24	94303	Palo Alto	39.5 ±1.3	46,879	14,466	14,447
25	94403	San Mateo	38.9 ±0.9	43,276	16,414	18,180

How we ranked them

Ranked by median age of all residents, highest first (ACS 5-year estimates, 2020–2024). ZIP codes need at least 1,000 residents to be ranked; 28 of 31 qualify.

Which of these to mail, and why

Older ZIP codes respond to health care, hearing and vision, Medicare plans, home safety, estate planning and services that come to the door.

The top five ZIP codes on this list hold 8,354 households. Open any of them on the route map to see each carrier route's own figures before you choose.

Open 94028 on the EDDM route map

More rankings

Businesses that mail these ZIP codes

Map it and price it

EDDM guides

Frequently asked questions

Which ZIP code in San Mateo County has the highest median age?: 94028 (Portola Valley), at 57.2 (±5.8), among 28 ZIP codes with at least 1,000 residents.
How is this ranking calculated?: Ranked by median age of all residents, highest first (ACS 5-year estimates, 2020–2024).
Why are some ZIP codes missing?: ZIP codes with fewer than 1,000 residents are left out because their survey estimates swing too much to rank, and so are ZIP codes where the Census Bureau did not publish this figure.

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.