WASHINGTON — Just when you thought you had the president’s health care law figured out, it’s changing.

Some questions and answers about what’s afoot and who’s affected:

Q: What’s the change, and why is President Barack Obama changing course now?

A: The president is letting insurance companies offer another year of coverage under their existing plans even if those plans don’t meet the requirements set out in his law. He’s doing so because of mounting frustration over the millions of cancellation notices going out to Americans whose plans don’t measure up to the law’s coverage standards.

Q: Problem solved?

A: Not so fast. Obama’s so-called fix doesn’t force insurance companies to do anything. It gives them the option of extending old plans for existing customers in the individual market, and only if state insurance commissioners also give their OK.

Q: Why wouldn’t insurance companies let people re-up?

A: The companies aren’t happy about being thrown a curve ball after they’ve already firmed up 2014 rates and plans. It will take a while to see how many of them agree to reinstate old plans for another year — and at what price.

Q: The changes mainly affect the 5 percent of people who get their own insurance policies through the individual market. What’s the big deal?

A: In a country of more than 300 million people, 5 percent is a big number. Roughly 14 million people buy their own policies, and many of those plans are not just junk insurance, contrary to what White House officials suggest. Already, more than 4 million people have gotten cancellation notices. And some small businesses are losing coverage for their workers too.

Plus, if the government can’t get its HealthCare.gov website running better by Dec. 15, some people who got cancellations run the risk of having a break in coverage.

Q: So people who successfully make the switch to the new insurance marketplaces can rest easy?

A: Not really. If lots of healthy people who get cheaper insurance through the individual market end up keeping that coverage instead of switching to the more robust plans offered through “Obamacare,” that could weaken the financial footing of plans offered by the insurance marketplaces.

Q: I get my insurance through my job. Do I need to worry?

A: The vast majority of people with employer-based plans shouldn’t be affected by the changes announced by Obama.