ImportancePrevious research has documented individual-level barriers to reproductive health services, but few studies have examined national trends.ObjectiveTo determine whether the number and type of barriers to reproductive health care experienced by US women of reproductive age changed from 2017 to 2021.Design, Setting, and ParticipantsThis cross-sectional study used serial survey data, weighted to be nationally representative, collected in August 2017 and December 2021 from members of Ipsos’s KnowledgePanel who were aged 18 to 49 years and assigned female at birth.ExposuresHaving experienced barriers to reproductive health care over the past 3 years.Main Outcomes and MeasuresThe primary outcome was number and type of barriers to reproductive health care services, including Papanicolaou tests or birth control, experienced in the past 3 years. Increases in barriers to reproductive health care were measured using multivariable linear regressions adjusted for age, race and ethnicity, education level, employment status, metropolitan area, geographic region, household income, and language (English vs Spanish).ResultsOf 29 496 KnowledgePanel members invited, 7022 (mean [SD] age, 33.9 [9.0] years) and 6841 (mean [SD] age, 34.2 [8.6] years) completed the 2017 and 2021 surveys (50% and 45% response rates, respectively). Among 12 351 participants who indicated that they had ever tried accessing reproductive health services, 35.9% (95% CI, 34.8%-37.0%) were aged 30 to 39 years; 5.5% (95% CI, 4.9%-6.2%) were Asian or Pacific Islander, 13.7% (95% CI, 12.8%-14.6%) were Black, 19.1% (95% CI, 18.1%-20.1%) were Hispanic, 58.2% (95% CI, 57.0%-59.5%) were White, and 3.5% (95% CI, 3.1%-4.0%) were multiracial or of other race or ethnicity; and 11.7% (95% CI, 11.0%-12.5%) were living below 100% of the federal poverty level. Covariate distribution was similar across years. In bivariable analyses, participants were more likely to report experiencing a given barrier in the past 3 years in 2021 than in 2017 for all but 2 barriers. More people experienced 3 or more barriers in 2021 (18.6%; 95% CI, 17.3%-20.0%) than in 2017 (16.1%; 95% CI, 14.9%-17.4%) (P = .008). In multivariable analyses, the mean number of barriers increased significantly from 1.09 (95% CI, 1.02-1.14) in 2017 to 1.29 (95% CI, 1.22-1.37) (P < .001) in 2021. Participants who were aged 25 to 29 years (0.42; 95% CI, 0.37-0.47), identified as Hispanic (0.41; 95% CI, 0.38-0.45), had no high school diploma or General Educational Development test (0.62; 95% CI, 0.53-0.72), lived below 100% of the federal poverty level (0.65; 95% CI, 0.55-0.73), and took the survey in Spanish (0.87; 95% CI, 0.73-1.01) saw the greatest increases in mean number of barriers between 2017 and 2021.Conclusions and RelevanceThe study findings suggest that barriers to reproductive health care increased between 2017 and 2021, with the largest increases observed among individuals from historically disadvantaged populations. Efforts are needed to ensure that reproductive health care access remains a priority.