States have come a long way in building longitudinal data systems in just three years, but dire budget conditions will not make it easy to finish them. Forty-two states can now report uniform graduation-rate data. All but two states can match test records for individual students from year to year. And 29 states track individual students' college-readiness test scores. Yet states have a long way to go before they have the kinds of data systems that will help drive student improvement, according to the latest progress report from the 3-year-old Data Quality Campaign, which works to improve state systems. Only 21 states have a teacher-identifier system that can match student-achievement data with individual teachers, and only 17 states collect information on which courses students have completed, according to the report released in November 2008. Although states have made progress toward creating data systems with 10 elements identified as essential to improving schools, such progress on data was seen as threatened because of political and financial problems. A shortage of resources, plus political challenges, makes one data point the most difficult: establishing teacher-identifier systems to match student-achievement data with individual teachers. This article reports on how states are tackling the challenge in different ways.