The Future of Music Coalition has lots of info on artists and the ACA:
Starting today, musicians and artists are invited to visit Artists and the Affordable Care Act. The website includes an FAQ, a list of artist-focused educational events and seminars, and links to videos and online calculators. There’s also a staffed musician-friendly hotline at 1-919-264-0418, and artists can email their questions to email@example.com.
ThinkProgress: Why The Affordable Care Act Matters To Artists:
[T]he Affordable Care Act matters to artists–just as it matters to a lot of entrepreneurs–because it makes it easier to take chances and carve out the time that makes it possible to pursue an artistic career. These aren’t folks who are demanding instant success, or a lot of money for their art, or even consistent rather than seasonal or contract employment. Instead, they’re people who want to lower their overall level of risk, and are more than willing to pay to afford to do so. They’re folks who would like to set up their lives so that when bad medical things happen, they are merely bad, even very bad, rather than completely catastrophic.
And from the comments on that article, this quote:
Lots of union actors and musicians may not work enough to qualify for union coverage, so the ACA is a godsend for them.