State demographer: Larimer County faces slower growth, aging population and housing pressures

Neil Marquez, a demographer with the Colorado State Demography Office, told Larimer County commissioners on Feb. 18 that the county is likely to see continued population growth but at a slower rate than in past decades as its population ages and fertility remains low.

Marquez said two forces largely determine population change: natural change (births minus deaths) and net migration. He noted that Colorado'wide, births are forecast to be overtaken by deaths by about 2047, and he warned that Larimer County is likely to reach that inflection point sooner because its fertility rate is depressed by a large university-age population.

Why it matters: an older population affects the tax base and service demand. Marquez said incomes and tax contributions typically peak in mid-career, and retirement-age cohorts contribute less in taxes while often requiring more services. He cited a worker-to-retiree ratio that has fallen to just above two working-age adults for every retiree by 2024, a shift that can reduce revenue while increasing pension, health and social-service needs.

The demographer said Colorado's recent migration pattern is also shifting. Historically, Colorado's growth has been driven by domestic migration tied to jobs, but post-2022 increases were disproportionately international and included asylum-related flows. Marquez said those international flows fell sharply beginning in 2024 and into 2025, creating a short-term decline in net migration that reduced revisions to county forecasts.

Marquez flagged other recent data points: international migration to Colorado has fallen substantially in recent data, he said, while births in 2025 rose compared with recent years with increases concentrated among older parents (roughly ages 30'44). He also described how small percentage changes in student-age migration can translate into large absolute swings for a county with a sizable student population.

Housing and affordability: commissioners pressed Marquez on housing's role in migration. He said Colorado and Larimer have become less affordable and that, while housing production increased relative to population growth in recent years, affordability remains strained. Marquez noted that rent and price declines in some metro areas have been concentrated among newer, higher-end units, while older units remain expensive. He said the county may need different unit types to match changing household composition as the population ages.

Data granularity and rural needs: commissioners asked whether the demographer's office can provide more granular data for rural communities. Marquez said federal sources (Census and other administrative data) can be limited at fine geographic scales but encouraged local governments to share on-the-ground data; he pointed to the 2030 census block-boundary review as a longer-term mechanism to improve local alignment.

What's next: Rebecca Everett, Larimer County community development director, said the presentation lays a foundation for an upcoming county work session that will present the housing needs assessment for Larimer County in the coming weeks. Marquez encouraged commissioners to follow up with the state office for more detailed questions and local data exchanges.

Commissioners and staff did not take formal action at the meeting; the session was a presentation and discussion.