IMPORTANCE As US adults approach Medicare eligibility at age 65 years, they face important decisions about health care and employment. Recent legislative, regulatory, and legal challenges to the Affordable Care Act may add new uncertainties to this decision-making. OBJECTIVE To understand adults' perspectives on health insurance, health care, and employment near retirement. DESIGN, SETTING, AND PARTICIPANTS In October 2018, a cross-sectional online survey study of community-dwelling US adults aged 50 to 64 years was conducted with Ipsos KnowledgePanel, a nationally representative internet survey panel (completion rate, 62%). The initial data analysis was conducted from November 2018 to March 2019, and additional analyses were conducted in November 2019. MAIN OUTCOMES AND MEASURES Confidence in affording health insurance, keeping a job or delaying retirement to have employer-sponsored health insurance, concerns about potential changes to health insurance associated with changes in federal policies, and avoidance of medical care or medication because of cost. RESULTS Among 1028 respondents aged 50 to 64 years (mean [SD] age, 57.0 [4.2] years), 51.8% (95% CI, 48.6%-55.0%) were female, 40.4% (95% CI, 37.2%-43.7%) had a high school education or less, 65.2% (95% CI, 62.1%-68.3%) were employed, and 34.8% (95% CI, 31.7%-37.9%) were retired or not working. Approximately one-fourth of respondents (27.4%; 95% CI, 24.6%-30.4%) had little to no confidence in being able to afford health insurance over the next year, and nearly one-half (44.6%; 95% CI, 41.4%-47.8%) had little to no confidence in their ability to afford health insurance when they retire; 14.1% (95% CI, 12.0%-16.5%) reported keeping a job and 11.4% (95% CI, 9.6%-13.6%) reported delaying or considering delaying retirement to have employer-sponsored health insurance. Most respondents (67.7%; 95% CI, 64.6%-70.6%) were very or somewhat concerned about potential changes to their health insurance associated with changes in federal policies. In the past year, 13.2% (95% CI, 11.2%-15.5%) of respondents did not get medical care and 11.9% (95% CI, 9.9%-14.1%) avoided filling a prescription medication because of cost. After adjusting for demographic and health characteristics, individuals with low confidence in health insurance affordability during either the next year or retirement were significantly more likely than those with higher confidence to avoid medical care (adjusted odds ratio, 2.89; 95% CI, 1.86-4.49; P < .001) and to avoid filling a prescription medication (adjusted odds ratio, 2.87; 95% CI, 1.71-4.80; P < .001) because of cost concerns. CONCLUSIONS AND RELEVANCE Many adults aged 50 to 64 years worry about their ability to afford health insurance during retirement and about potential future changes to their health (continued)