As employers try to minimize expenses under the health law, the Obama administration has warned them against paying high-cost workers to leave the company medical plan and buy coverage elsewhere.

Such a move would unlawfully discriminate against employees based on their health status, three federal agencies said in a bulletin issued this month.

Brokers and consultants have been offering to save large employers money by shifting workers with expensive conditions such as hepatitis or hemophilia into insurance marketplace exchanges established by the health law, Kaiser Health News reported in May.

The Affordable Care Act requires exchange plans to accept all applicants at pre-established prices, regardless of existing illness.

Because most large employers are self-insured, moving even one high-cost worker out of the company plan could save a company hundreds of thousands of dollars a year. That’s far more than the $10,000 or so it might give an employee to pay for an exchange plan’s premiums.

“Rather than eliminating coverage for all employees, some employers … have considered paying high-cost claimants relatively large amounts if they will waive coverage under the employer’s plan,” Lockton Companies, a large brokerage, said in a recent memo to clients.

The trend concerns consumer advocates because it threatens to erode employer-based coverage and drive up costs and premiums in the marketplace plans, which would absorb the expense of the sick employees.  The burden would fall on consumers buying the plans and taxpayers subsidizing them.

Administration officials approached independent lawyers about the practice in May, saying, “We don’t like this, but how can we address this?” said Christopher Condeluci, principal at CC Law & Policy, a legal firm. This month’s guidance, he said, “is the first time that they’ve come out explaining how and why the administration believes it violates the law.”

The Affordable Care Act itself doesn’t block companies from paying sick workers to find coverage elsewhere, lawyers said. But other laws do, including the Health Insurance Portability and Accountability Act and the Public Health Service Act, according to three federal agencies.

Specifically, paying a sick worker to leave the company plan violates those statutes’ restrictions on discriminating against employees based on medical status, the departments said in their bulletin.

“If you were to cherry-pick your high-cost individuals and offer them money to send them over to the exchange … this would be a violation of HIPAA,” according to the regulators, said Amy Gordon, a benefits lawyer with McDermott Will & Emery.

The agencies publishing the guidance were the departments of Labor, Treasury and Health and Human Services.

Starting next year, the health law requires large employers to provide medical insurance to most workers or face fines.

How many companies have offered to pay workers with chronic conditions to find coverage elsewhere is unclear.

“I know there are some brokers out there that were pushing this, but it was a limited number that I had heard about,” Condeluci said. Even so, he added, the attitude of the administration was: “We don’t want it to become widespread. Let’s nip it in the bud now.”

Kaiser Health News (KHN) is a national health policy news service. It is an editorially independent program of the Henry J. Kaiser Family Foundation.

So far, the open enrollment period on the federal and state marketplaces—which started Nov. 15 and continues until Feb. 15 for 2015 coverage—is proceeding much more smoothly than last year. But people remain confused about plans, premiums and provider networks. Here are answers to several readers’ questions.

Q. I understand the federal marketplace will renew my coverage automatically this year. That seems really simple. Is there any reason I shouldn’t do it?

A. There’s every reason not to auto-renew, particularly if you’re one of the many people who receive premium tax credits, experts say.

If you do nothing, you’ll generally be automatically re-enrolled in your current 2014 plan and receive the same premium tax credit amount that you qualified for in 2014. That’s probably not in your best interest.

For one thing, the number of plans is increasing about 25 percent, so you may find a better plan at a better price. Although premium increases are modest overall, some plans are raising or lowering their rates significantly next year, and yours may be one of them.

In addition, the plan that was the best option for you last year may have changed for 2015. Even though the insurer will re-enroll you in a plan it considers most similar to your 2014 plan, crucial details related to covered benefits, drug formularies, cost sharing and provider networks could be different, says Timothy Jost, a law professor at Washington and Lee University who is an expert on the health law.

If you’re one of the roughly 85 percent of people on a marketplace plan who receives tax credits to help make premiums more affordable, you could face a big premium hike if you don’t re-evaluate your options and choose a low-cost plan.

Premium tax credits, which are available to people with incomes between 100 and 400 percent of the federal poverty level (currently $11,670 to $46,680 for an individual) are based on the second-lowest-cost silver plan in your area. In 2015, that benchmark plan may have changed. If that’s the case, even if your current plan’s premium doesn’t increase, you may owe more if you don’t switch plans because you’ll be on the hook for the premium difference between the new, lower benchmark plan and your existing plan.

Q. I called my doctor’s office to find out if they accept any of the marketplace plans I’m considering, and they said they don’t accept any Obamacare plans. Can that be true?

A. It’s possible, say experts, but you need to check further before you take no for an answer.

The pertinent question is whether your doctor has a contract with the insurer in question to participate in a particular plan. If she does, “there shouldn’t be a difference whether that person buys the plan in the marketplace or not,” says Sarah Lueck, a senior policy analyst at the Center on Budget and Policy Priorities. From the insurer’s perspective, it’s the same plan, no matter where it’s offered.

In some cases, doctors sign contracts with insurers containing “all-product” clauses that obligate them to participate in any network the insurer chooses to have them in, says Sabrina Corlette, project director at Georgetown University’s Center on Health Insurance Reforms. Doctors may not realize they signed a contract with an all-product clause, leading them to provide inaccurate information. This can be frustrating for both doctor and patient.

To get the correct answer from your doctor’s office, you need to know the name of the insurer and the exact name of the plan you’re considering, says Jennifer Tolbert, director of state health reform at the Kaiser Family Foundation. (KHN is an editorially independent program of the foundation.) It’s a good idea to check with the insurer as well to see if your doctor’s name appears on their list of participating physicians for a particular plan.

Q. My doctor is in network, but the hospital he has admitting privileges at isn’t. What happens if I need to go to the hospital?

A. Some policy experts say this situation appears to be occurring more frequently as insurers in some cases exclude higher-cost hospitals, such as academic medical centers, from exchange plans with narrow networks.

If you have to be hospitalized next year and want to stay in-network, you may have to make a choice between your doctor and a hospital.

“Because the hospital expenses are going to be so high, you’re probably going to want to go to the hospital that’s in-network and just use a physician that has admitting privileges there,” says Tolbert.

Of course, you could choose to go to an out-of-network hospital, but that could leave you on the hook for the entire bill, depending on your plan.

Please contact Kaiser Health News to send comments or ideas for future topics for the Insuring Your Health column.

Kaiser Health News (KHN) is a national health policy news service. It is an editorially independent program of the Henry J. Kaiser Family Foundation.