The importance of the administrative burden problem in public programs has been apparent during the COVID-19 crisis in the United States as millions of newly unemployed people have had to wait for unemployment checks and public health insurance benefits due to paperwork requirements, agency staff shortages, and outdated information technology systems. The resulting burdens have extended financial hardship, caused the coronavirus to spread, and eroded citizen and agency morale. Administrative burdens have long been known to be costly, yet remain fixtures of public benefit programs across the world. To reduce them, we need to understand their mechanisms. Formal policy solutions per se will not reduce administrative burdens because they do not exist solely by design. This article contributes to behavioral public administration by providing a comprehensive, empirical-driven theoretical framework for understanding the complex processes through which supply-side administrative burdens are instituted, modified, and eliminated. Using a retrospective within-case study method that utilizes participant observation, documentation, and archival records, the article traces the process by which a state eliminated administrative burdens in the process of implementing an initially straightforward expansion of Medicaid eligibility, thereby creating a model for simplifying and streamlining enrollment that was incorporated into the Affordable Care Act.