Words of Encouragement

An action-oriented letter encouraging applicants to complete their already started health insurance enrollment proved effective.

a graph with numbers and points

Read Time: 2 minutes


If you’ve ever gotten distracted halfway through an online application process, what would make you finish it?

Every year, hundreds of thousands of people begin the Affordable Care Act marketplace open enrollment process but don’t complete it. This leads to “coverage gaps,” where people miss out on obtaining needed health insurance.

David Yokum and colleagues tested a low-cost intervention in the final weeks of the 2015 HealthCare.gov open enrollment period to encourage more people to complete the process. The trial targeted 744,510 individuals who had started and abandoned their online application. Participants were randomly selected to receive one of eight types of encouragement letters.

Each intervention group got a different letter in the mail encouraging them to complete enrollment. The “basic” letter stated it was “time to come back” and “not too late” to complete enrollment. “Action” letters emphasized the deadline, and some included a calendar showing the dates remaining to enroll or a picture of the Marketplace CEO. “Social norm” letters encouraged joining other Americans in enrolling, while the “loss aversion” letter highlighted the financial risk of not doing so. Finally, the “kitchen sink” letter combined multiple strategies.

Enrollment among all groups was 0.3% higher than enrollment in the no-letter control group. The three “action” letters, as shown in the graph, proved the most effective, costing about $104 per new enrollee compared to $742 per enrollee for the least effective letter.

The American Rescue Plan, passed by Congress in March 2021, expanded eligibility for affordable health care. However, recent surveys of uninsured adults found that the majority still lack awareness of the ACA marketplace. The authors offer a blueprint to reduce the number of people who remain uninsured: a simple letter encouraging Americans to get online and try again.

Databyte via David Yokum, Daniel J. Hopkins, Andrew Feher, Elana Safran, Joshua Peck. Effectiveness of Behaviorally Informed Letters on Health Insurance Marketplace EnrollmentA Randomized Clinical Trial. JAMA Health Forum, 2022.