Q What if I don't have insurance?

A Nothing happens right away. Beginning in 2014, virtually all Americans will have to obtain coverage or pay a tax penalty. For a single person the penalty will start at $95 per year or up to 1 percent of income, whichever is greater. The penalty becomes larger from 2014 through 2016. You are exempt from the penalty for certain reasons of financial hardship.

Q My employer doesn't offer insurance and I can't afford to buy it on my own. What are my options?

A Starting in 2014, you will be able to buy private plans through state-based marketplaces. The exchanges are a way to comparison shop and buy private plans. If your income is low enough, you could qualify for federal subsidies or qualify for Medicaid, which will be expanded to cover individuals and families with incomes at or below 133 percent of the federal poverty level. (Some people with higher incomes may be eligible.) But it's unclear whether all states will expand Medicaid since the court said the government cannot force states to do so.

Q I have been refused insurance because I have a pre-existing medical condition. How can I obtain coverage?

A You may be able to buy it through "high-risk pools" the law has set up in each state, through the end of 2013. But the premiums in the pools vary and can be high. Starting in 2014, insurers will no longer be able to deny you coverage or charge you higher rates for having a pre-existing condition.

Q Will my insurance rate go up?

A Some of the rules imposed on insurers could contribute to an increase in your premium, with analysis from the nonpartisan Congressional Budget Office showing increases of $100 to $200 a year for insurance through work. But rate may go up for reasons unrelated to the law, such as if medical costs in your area have increased.

Q Can my insurance company cancel my plan if I get sick?

A No, technicalities cannot be used to cancel your plan if you become ill.

Q What other rules are in place?

A Insurers can't discriminate against children with a pre-existing condition. They also cannot set a lifetime limit on benefit payouts. Any annual limits will be phased out by 2014.

Q I lost my job and have insurance through COBRA. What will happen?

A Not much now. But once the exchanges and subsidies are set up in 2014, they will effectively replace COBRA. So if you leave or lose your job then, you will no longer have the option of staying on your former employer's plan for up to 18 months. Instead, you will be able to buy coverage through your state's exchange.

Q Can young adult children stay on their parents' insurance plans?

A Children can stay on your plan until they are 26 -- unless they have insurance through an employer, and your plan predates Sept. 23, 2010.

Q Will my Medicaid benefits change?

A For now, no. If you live in a state that was offering Medicaid to a larger share of the poor than required by federal rules, the law has required your state to lock in those eligibility rules through 2014. At that point, your state will have to decide whether to participate in the Medicaid expansion.

Q Will my Medicare benefits change?

A New benefits remain in effect, including coverage of preventive care without co-pays or other out-of-pocket charges. The prescription-drug coverage gap will be narrowed each year until it is eliminated by 2020. This year, if your drug expenses put you in that gap, drug-makers must give you a 50 percent discount on all brand-name drugs. The government also has begun to provide some relief on generics, covering 14 percent of their cost for those in the gap. Higher earners will have to pay higher premiums for prescription drug coverage.