Congressional lobbying by education-related interest groups is an understudied subject in education research. This brief uses congressional lobbying expenditure data from 1998 to 2017 to examine trends in lobbying behavior by labor unions; K-12 education providers; and public, private nonprofit, and for-profit higher education institutions. Education interest groups have spent in excess of $2 billion lobbying Congress since 1998. Higher education institutions represent a disproportionate share of lobbying activity and expenditures, accounting for almost 70% of education-focused interest groups and around 80% of education-related lobbying expenditures. Lobbying expenditures steadily rose until 2011 before rapidly declining. The brief speculates as to the possible reasons for these trends and concludes with a call for greater research on lobbying for education.