Which ZIP code in DeKalb County has the highest median age?

60552 (Somonauk), at 48.6 (±6.8), among 14 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 DeKalb County, IL

These are the 14 ZIP codes in DeKalb County with the highest median age, out of 14 with at least 1,000 residents. 60552 (Somonauk, 48.6), 60151 (Maple Park, 44.1) and 60518 (Earlville, 41.9) lead the list. There is no single "best" ZIP code in DeKalb 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 DeKalb County

Rank	ZIP	Mailing city	Median age	Residents	Households	Residential mailboxes
1	60552	Somonauk	48.6 ±6.8	4,285	1,807	1,557
2	60151	Maple Park	44.1 ±5.6	3,888	1,437	1,520
3	60518	Earlville	41.9 ±4.7	3,289	1,465	1,255
4	60146	Kirkland	41.1 ±6.4	2,369	968	616
5	60548	Sandwich	40.8 ±3.2	11,721	4,548	5,002
6	60135	Genoa	38.9 ±7.5	7,274	2,901	2,841
7	60531	Leland	38.2 ±2.5	1,885	724	547
8	60520	Hinckley	37.9 ±3.1	2,979	1,123	1,055
9	60178	Sycamore	37.0 ±1.9	22,224	8,735	9,583
10	60145	Kingston	36.8 ±4.1	2,464	900	878
11	60150	Malta	33.9 ±5.3	1,738	591	479
12	60112	Cortland	31.5 ±3.2	4,621	1,599	1,748
13	60556	Waterman	30.0 ±4.0	2,138	719	733
14	60115	Dekalb	26.4 ±0.8	42,536	17,262	17,358

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; 14 of 18 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 10,225 households, on 22 carrier routes with 9,950 residential mailboxes. Open any of them on the route map to see each carrier route's own figures before you choose.

Open 60552 on the EDDM route map

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Businesses that mail these ZIP codes

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Frequently asked questions

Which ZIP code in DeKalb County has the highest median age?: 60552 (Somonauk), at 48.6 (±6.8), among 14 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.