there will be open enrollment periods during which you can select and purchase a health plan. the first year the aca takes effect it will run from october 1 2013 through march 31 2014. unless you experience what's called a "qualifying event" -- you get married have a baby divorce or otherwise lose existing health insurance coverage -- you will only be able to switch plans during the open enrollment periods.
what happens if you purchase a plan and then in the middle of next year your needs change?