Over the next five years, the effects of the ACA on employer-sponsored insurance will be modest. In the longer run, there is greater potential for disruption, depending on how firms respond to the subsidies available on the exchanges for low-wage workers. In all, only about 15% of the workforce likely will be affected. The impacts of the ACA on firms will vary widely based on three main factors: 1) the size of the firm, 2) the average compensation within the firm, and 3) the degree to which wages within the firm are homogenous or heterogeneous. Keeping in mind that employees pay for all their health insurance, group insurance is not intrinsically superior to private exchanges, and cost trumps choice for consumers, firms will choose the option that maximizes benefits to their workers, takes advantage of the best available subsidies while avoiding tax penalties, and results in the lowest administrative costs. Making all low-wage workers eligible for the same subsidies, whether they acquire coverage on the exchanges or in group plans, would be reasonable and involve less distortions.