Dairy cattle longevity averages approximately 3 years after first calving, despite improvements in genetics and cow comfort over the past several decades. The natural life span of cattle is about 20 yr. In some parts of Western agriculture, there is a strong push to extend dairy cattle longevity. Our objectives are to first explore economic and environmental incentives for increasing average dairy cattle longevity and then discuss deterrents to increasing longevity. The vast majority of culling decisions, and by extension of dairy cattle longevity, are driven by economic decision-making. Younger herds capitalize on genetic progress but have fewer efficient mature cows and greater replacement costs. There is also a growing interest in the use of beef semen in dairy cattle, which does not add to the supply of dairy heifers. High premiums for crossbred calves suggest a greater marginal value of extending dairy cattle longevity. Extending dairy cattle longevity might also decrease the environmental footprint of milk production. Historically, models focused on optimizing culling decisions for individual cows, while assuming an unlimited supply of heifers, found optimal cull rates of approximately 30%. This suggests a slightly longer longevity than is currently observed. However, cow performance has changed and the average findings of these models may no longer be optimal. Some consider a short longevity a result of unavoidable forced culling and a welfare issue. Management and housing may affect longevity by improving health care and cow comfort. On the other hand, this short longevity is also driven by an abundance of replacement dairy heifers now available through the use of sexed semen and good reproduction. The dairy community should reevaluate how many dairy heifers are needed, which animals should be the dams, and what to do with animals that do not need to supply replacements. Genetic selection, cow comfort, and health care will increase the ability of cattle to avoid culling for forced reasons. These topics are interdependent and will drive future changes in dairy cattle longevity.