Background/Objectives: The Brazilian Unified Health System was established in 1988 as a public health system with principles of universality, equity, and integrality. One of Brazil’s main strategies to strengthen universal healthcare is the Family Health Strategy (FHS), a primary health care policy established in 1994 and fully incorporated in the country in 2006. This study aims to describe the time trends of FHS coverage in Brazil and its states from 2008 to 2023 and to correlate this coverage with the states’ Human Development Index (HDI). Methods: Data on the number of FHS teams, population, and HDI during the period were collected for each Brazilian state in the Brazilian Ministry of Health’s public-access databases. Prais–Winsten regression was used to conduct a time series analysis for each state and country. The annual percentage change (APC) was used to describe time trends in time series. Linear regression was used to identify a correlation between HDI and FHS coverage across states. Results: The FHS coverage in the country increased from 66.81% to 84.66% from 2009 to 2023. Disparities in coverage between regions are evident throughout the entire study period. The Northeast region (NE) exhibited higher FHS coverage but lower APC rates compared to other regions. Results suggest a negative correlation between HDI and FHS coverage in all Brazilian states for 2009, 2012, 2015, 2018, 2021, and 2023. Conclusions: The FHS coverage increased in Brazil and its states during the period. The highest coverages were found in states from the North (N) and NE regions, and the lowest were in the Southeast region. Nine federative units achieved full coverage (100%) and maintained it afterward, with seven from the N and NE. A negative correlation was found between FHS and HDI, suggesting that the expansion of FHS effectively targets vulnerable populations.