Not long ago, academic scientists welcomed calls from the National Institutes of Health (NIH) asking them to volunteer as peer reviewers. Many were glad for the opportunity to help distribute billions of dollars in federal biomedical-research grants even though the service required a big time commitment--the equivalent of one month a year to evaluate grant applications and travel three times annually to the NIH's headquarters in Maryland for meetings of peer-review committees. While the scientists reaped personal benefits, some scientists say it seems more and more like a frustrating, even dreary chore. They argue that the agency is struggling to recruit the most talented reviewers in some fields--and that as a result, the quality of science supported by the NIH, the largest single source of funds for academic research, is at risk. One culprit for that shift in attitude is a decline in the agency's budget since 2003, which in turn has reduced the percentage of grant applications awarded money. That makes many reviewers feel that the long hours of work they donate are for naught. This article describes how NIH is considering changing its policies to entice more senior scholars to evaluate grant applications.