Over the past 50 years, 16 states, the District of Columbia, and 106 local governments have passed laws that prohibit landlords from discriminating against tenants who receive housing choice vouchers. These laws generally outlaw discrimination based on the tenant’s “source of income,” whether that source is a job, a pension, alimony, or government assistance. Using a new Urban Institute dataset that includes details on these laws, we find that that source of income protections help families access low-poverty neighborhoods. But these laws take five years, on average, to make an impact. We find that before the laws were enacted, the share of households with children moving into low-poverty neighborhoods was falling relative to expectations. Once the protections took effect, this decline continued for three to four years before reversing. Between four and eight years after the laws took effect, the share of these households moving into low-poverty neighborhoods was greater than the year before the law took effect. Both the preprotection declines in access to low-poverty neighborhoods and the improvements after laws were passed were larger among Black families than for white or Hispanic/Latinx families. More research is needed to understand the delay between the enactment of these laws and their effects, to better understand how source of income protections might affect some households differently than others, and to determine whether other policies or programs need to be enacted for source of income protections to be effective.