I've said before that there are a few areas of the ACA which I simply don't consider myself knowledgable enough about to try and explain to others in depth. One of these is the so-called "Cadillac Tax" on high-end employer sponsored insurance policies. The other (well 3 others, really) are the "3R" programs which were set up to try and smooth out the transition period for insurance carriers for the first few years. The "3 R's" are "Risk Adjustment", "Reinsurrance" and "Risk Corridors".
Risk adjustment is a process that deters insurance plans from trying to attract healthy enrollees (“cherry picking”), and protects companies that may—by chance or because of their particular benefits—attract sicker than average customers (“adverse risk selection”). Though the Affordable Care Act bans carriers from turning people down or charging them more based on their health, the incentive to attract healthier enrollees remains because healthier customers increase profits by reducing companies’ payouts.