Lake San Marcos, CA population, income and ZIP codes

Lake San Marcos CDP is a small town in California, with 4,996 residents counted in the Census American Community Survey 2019-2023 ACS 5-year estimates, which places it #662 of 1,618 ranked by population — larger than 59% of them. The median age here is 60.1 years against 39.1 nationally, a markedly older profile that usually tracks retirees staying put and younger households leaving for work. At this population the ACS sample is small, so the margin of error around every dollar figure below is wide — treat the numbers as a band, not a point, and expect them to move between annual releases without the place itself changing.

Households in Lake San Marcos CDP earn a median of $100,676 a year, 28.2% above the national figure of $78,538 and 10% above the $91,111 median for the 1,050 California cities we cover. Household income here is measured before tax and pooled across everyone at the address, which is why it reads higher than typical individual earnings in the same area. Poverty reaches 6.3% of residents here, below the 12.4% national rate.

The typical owner-occupied home in Lake San Marcos CDP is valued at $859,600, 183.3% above the national figure and 46% above the $589,600 peer median, while median gross rent runs $2,615 a month, 86% above the national figure, or roughly $31,380 across a full year. A household on the local median income would put about 31.2% of gross pay toward that rent against the federal 30% cost-burden threshold, so renting here is a stretch on median earnings. The home-price-to-income ratio works out to 8.5×, against roughly 3.9× nationally, so buying is out of reach on local earnings alone and the ownership market leans on outside income, equity or dual high earners. 78.4% of occupied homes are owner-occupied versus 65% nationally, so the market leans toward owners. Rent is reported gross — contract rent plus tenant-paid utilities — which is why it runs above the advertised price on a listing for the same unit.

Home values sit at 8.5× median household income, far past the 3.9× national mark, so ownership costs here are set by something other than local wages — second homes, retirees with equity, or commuters earning elsewhere. A median age of 60.1 puts Lake San Marcos CDP well into retirement-weighted territory, which pulls median household income down even where household wealth is high, because retirement draws are counted differently from wages.

No figure on this page is estimated by us; each one comes straight from the published ACS tables for this area. Small-area estimates still carry wider margins of error than state or national figures, so check the linked ACS tables before relying on them for lending, appraisal or legal work.