Provided you have insurance in the first place. (The rest of this post is seemingly invalid in California:) Contractor? No, you don't get insurance. Don't you have COBRA? You can't afford that? Well, golly, better hope that you don't get sick.
If you're a contractor w/o insurance, you're doing it wrong. You should be setting rates so that you can afford insurance.
Health insurance, business insurance, vacation time, holiday time, sick time, equipment, etc. All of these things go into the calculations for your rates.
Indeed. The GP's question was about "American employees", which I interpreted as "full-time employees at a company in the USA".
Contractors are subject to the health care plans of the company they work for (or whatever they buy on the individual market, if they are self-employed). Part-time employees (less than 30 hours per week, IIRC, although that's probably state-by-state) also receive different treatment. Some companies have started to manage hours to have more part-time workers instead of fewer full-time workers as a means to game the heath care laws: http://www.washingtonpost.com/blogs/wonkblog/wp/2013/05/06/w...