In this paper, we take a new approach to the question of whether or not intentions regarding future fertility affect fertility-related behavior. Our approach has three principal features: 1) it takes sterilization as its outcome, rather than pregnancy or birth; 2) it is based on a conceptual model in which fertility-related behavior is seen as determined by a long-range planning process, modified by unanticipated life course contingencies; and 3) it uses data on desired total family size. Using data from the National Survey of Families and Households, we find that achieving one's desired parity has a strong, persistent, and positive effect on the probability of sterilization, supporting our view of the long-term nature of fertility intentions. People do modify their behavior in the face of unanticipated contingencies, but those effects are unexpectedly small.