While web surveys allow for fast and inexpensive data collection, they are subject to coverage error if respondents cannot be included because they cannot be identified or contacted (Groves et al. 2004). Coverage error is of particular importance in web surveys where often there is no listing of the population and their email addresses (Couper 2000). If a listing of email addresses exists, it may be incomplete or out of date. Firewalls or other security features may prevent an email from reaching even valid email addresses. In 2012-2013 Abt SRBI implemented the Survey of Scholarships in Science, Technology, Engineering, and Math (S-STEM) Recipients, a web survey to understand the effects of an undergraduate scholarship program on current and former students' college and work experience. The National Science Foundation (NSF) provided the sample which consisted of S- STEM recipients that received funding between 2006 and 2012. Most (97%) recipients had an email address listed in the sample file, but because the email address originated from the email given at the date of scholarship award, 55% of those addresses were four years old or older. In this research we describe efforts we undertook to verify email addresses in the sample and to improve contact rates. These efforts include telephone, mail, and internet based locating, commercial email location services, and alternating the sources of the email invitation between the study sponsor and the contractor. We report on the contact and completion rates by type of effort and total level of effort. We explore the relationship between coverage loss and certain sample characteristics such as student age, gender, major, and degree obtained as well as institution type (2 year or 4-year), region, and years since the scholarship was funded. The results will help optimize coverage in future web surveys of students with a listed sample.