Ericson et al in RESTUD report on a randomized control trial on ACA enrollment in Massachusetts. They provided information or a streamlined enrollment process.

We conducted a randomized controlled trial with Massachusetts’ Affordable Care Act marketplace to reduce these barriers and other behavioral frictions. We find that a “check the box” streamlined enrollment intervention raises enrollment by 10.5%, more than personalized reminder letters (7.6% increase) or generic reminder letters (4.3% increase). Effects are concentrated among individuals eligible for zero-premium plans, who faced no further administrative burdens of setting up payments…

Compared to standard operating procedures, our streamlined enrollment treatment raises take-up among our sample population by 3.2 percentage points (10.5% of baseline; p < 001); baseline enrollment is 30.4%. The effect is much larger for individuals who were eligible for zero-premium plans (6.1 pp, 22.3% of baseline for our zero-premium eligible sample; p < 001).

State based marketplaces can make process changes to their enrollment procedures at likely far less costs than throwing money at people. The fact that zero premium plan exposed individuals is highly responsive to reducing enrollment barriers strongly implies that cash is not always the problem as there is no cash barrier for folks who are zero premium eligible.

States can make policy independent of the federal government and these policies can be extremely effective.