effectuated enrollment

A person can enroll in a health plan (ie, create an account with the exchange or the health insurance company and make a plan selection) without paying any premiums. But if they don't pay their initial premium, the plan never actually takes effect – in other words, it doesn't get effectuated. So the term "effectuated enrollments" is used to describe the number of people who have enrolled in coverage and also paid whatever premiums are due in order for their coverage to take effect and remain in effect.

Several million people enroll in individual market coverage through the ACA-created health insurance exchanges each year. The federal government provides data early in the year in terms of how many people selected a plan during open enrollment. But some of those people don't pay their initial premiums, and others stop paying their premiums (or actively cancel their policies) later in the year. So effectuated enrollment data give us a clearer picture of how many people actually have coverage.

As of February 2018, effectuated enrollment in the exchanges nationwide stood at about 10.6 million people (as opposed to 11.8 million people who had selected plans during open enrollment). By June 2018, it had dropped a little, to 10.3 million people. This drop-off makes sense, since people can drop their coverage (or just stop paying their premiums) at any point during the year, but enrollment outside of open enrollment is limited to those who experience a qualifying event. So effectuated enrollment tends to peak early in the year, right after open enrollment, and then decline slowly throughout the year.