While undergraduates in the STEM and SBE fields tend to accumulate considerable student loan debt, this AIR Data Brief finds the opposite is true for many individuals pursuing doctorates in the sciences. Early debt accumulation at the undergraduate level can have dramatic implications for participation in advanced degrees, the brief explains. This data brief is the third of four in the series. (See the first at ED558216; the second at ED558222; and the fourth at ED558229.]