Under this grant, Mark Hall and Mike McCue will leverage several data sources to answer the following questions: 1) How the Trump administration’s looser restrictions on short-term plans affected the individual market; 2) If more lenient open- or special-enrollment rules, by state-based exchanges (and now a new federal special enrollment period under the Biden administration) have led to, or will lead to, adverse selection; and 3) Whether market conditions would favor lessening or removing the firewall between the individual and small-group markets. As in prior years, Hall and McCue will use financial information insurers file with the federal government to comply with the Affordable Care Act’s rules regarding medical loss ratios and premium rate increases. They also will use financial data from the Center for Consumer Information and Insurance Oversight, the National Association of Insurance Commissioners’ financial filings, and other sources. Outcome measures include differences in enrollment, premiums, profit levels, medical loss ratios, and risk scores in states with different policy approaches in the areas of focus.