In the United States (US), the percentage of men who do not want more children increases from 43% among those between ages 25 to 34 years to 80% among men in their mid-30’s and early 40’s. Despite there being few differences in US men’s fertility intentions, Black, Latino and low-income men are more likely to be involved in unwanted pregnancies, which can contribute to the cycle of poverty. Vasectomy (i.e., male permanent contraception) is the most effective male contraceptive method for those who do not want more children. Black, Latino, and low-income men are far less likely to rely on vasectomy than White men and those with higher incomes, and these differences in use have persisted for decades. Vasectomy is also used less often than female sterilization in Black, Latino, and low-income communities, but use is more comparable to female sterilization among Whites and those with higher incomes. These different patterns of permanent contraception use may be related to differences in knowledge about vasectomy and its (lack of) effect on sexual functioning. Yet, even with accurate and meaningful information, demographic differences in vasectomy use may persist owing to difficulties finding and obtaining affordable care. There have been few efforts to comprehensively assess how differences in US men’s reliance on vasectomy are related to individual demand for the procedure and pathways to healthcare. The proposed study seeks to address key individual-level determinants of disparities in vasectomy use - men’s knowledge and decisional conflict about the method - to ensure all men are able to make informed, value-concordant decisions around contraception. Further, we will evaluate the common challenges that men who desire vasectomy encounter as they navigate to care. The specific aims of the study are to: 1) Build a patient-facing web-based decision aid to support informed decisions about vasectomy; 2) Assess the impact of the decision aid on vasectomy knowledge and decisional conflict in a randomized controlled trial with 750 men seeking information online about vasectomy or attending prenatal care or family planning visits in the US; and 3) Identify modifiable factors to obtaining a desired vasectomy and strategies to address them by prospectively assessing men’s experiences seeking care at 2 and 6 months and conducting in-depth interviews. This innovative study offers a new approach to directly address disparities in vasectomy knowledge by producing a scalable tool designed to enhance men’s informed contraceptive decision making and care navigation. This study will also enable us to identify other potential strategies that can facilitate timely, affordable access to desired vasectomy services.