The biggest changes in health insurance in a generation are set to take effect this year and next. Robert I. Field, a law and public health professor at Drexel University, answers questions about the changes stemming from the health law.

Insurance exchanges are coming. What are they?

An exchange is a marketplace where you can buy health insurance for you and your family. Most people will access them online, but there will be offices for those who prefer human contact. They will offer policies at four levels of coverage, named for precious metals. Platinum will be the best, followed by gold, silver, and bronze. Of course, the better the policy, the higher the premium.

Whom will it serve, and how will it work?

Exchanges are intended mainly for those who are unemployed, self-employed, or who work for companies without health benefits. If your employer offers coverage that meets minimum standards, or if you qualify for Medicare, Medicaid, or another program, you must get your insurance through those sources.

No one can be denied coverage due to a preexisting medical condition. If your income is lower than four times the federal poverty level (currently about $46,000 for an individual and $94,000 for a family of four), you will qualify for financial assistance, which will reduce the amount you pay. 

When do exchanges start?

They are set to open for business on Oct. 1. While some delay is possible, the government believes the timing is on track. When they open, you will be able to start shopping for an insurance policy. If you buy one, it will take effect on Jan. 1.

Will the health law cut Medicare benefits?

For most beneficiaries, no. In fact, some benefits will improve. The infamous gap in prescription-drug coverage known as the "doughnut hole" will gradually go away. Co-pays and deductibles will be eliminated for most preventive care, such as physical exams.

What comes next?

For most people, not much will change. That's because most Americans receive health insurance through an employer, and most of those plans will remain in effect.

On the other hand, those who buy policies on their own or who can't find coverage will see big changes, including the exchanges.

The other big change is that Medicaid will cover many more people starting Jan. 1 in about half the states, including New Jersey. Everyone with an income below 138 percent of the federal poverty level will be eligible (currently $15,856 for an individual and $32,499 for a family of four). But those who live in Pennsylvania will be out of luck. Unless the Corbett administration switches course, the commonwealth's Medicaid program will remain unchanged.

What if I don't buy health insurance? Can I go to jail?

With all the media attention to the law's requirement that everyone have health insurance, you would think the consequences for not complying would be dire. In fact, they are relatively mild. No one will go to jail or face criminal charges of any sort. The financial penalty is an assessment paid with the following year's tax return. For 2014, it will be the greater of $95 for an uninsured individual or 1 percent of taxable income. The minimum assessments for families will be three times those dollar figures.

Exemptions will be available for financial hardship and religious objections. If you choose to go uninsured and pay the penalty, you will have fully complied with the law, so there will be no further consequences unless you get sick or injured, in which case you won't have insurance to pay the bills.