Open enrollment for the health law’s 2016 marketplace plans begins Sunday, and federal officials caution consumers to check out premium prices because in many places they may be higher. But officials are planning to offer new features to make the process faster and smoother for consumers.

They can already do some window-shopping for plans on the federal marketplace, healthcare.gov.  A new feature that may help some customers is an online, out-of-pocket expense calculator on the website to help estimate how much they will pay in deductibles and co-payments in addition to the monthly premiums.

Additional tools to show if a particular plan includes a consumer’s doctor and what drugs are covered under an insurer’s list of approved drugs are still being tested and will debut later, officials at the Department Of Health And Human Services say.

The 2010 health law requires most Americans to have insurance or pay a fine. Starting Sunday consumers who do not get coverage through their work can begin signing up for next year’s plans on federal or state marketplaces. Subsidies are available to help many people afford coverage.  Medicaid enrollment can occur throughout the year and Medicare has its own enrollment period.

So far, 17.6 million uninsured people have gained coverage since the law was created, according to an HHS analysis.

HHS Secretary Sylvia M. Burwell told reporters earlier this month that the agency is aiming to have about 10 million people paying for exchange coverage by the end of 2016 – a goal she described as “strong and realistic.”

That is also about a million sign-ups more than expected by the end of this year and half of the Congressional Budget Office’s June projection of 20 million health law enrollees in 2016. Burwell has acknowledged that the next enrollment period will be challenging and that those still uninsured will be tougher to reach than those who have enrolled in the first two years of the marketplaces.

Here’s what you need to know for the coming enrollment period.

I enrolled on healthcare.gov last year. Do I have to do it again?

If you take no action, you will generally be reenrolled in your current plan or if it is not available something similar. But since some plans have changed and new plans are coming on the market, federal officials are encouraging people to go back on healthcare.gov to compare benefits and prices instead of relying on the automatic renewal. You should also update your income information to find out if you qualify for financial help to purchase coverage and to make sure you receive the correct amount. That’s because your subsidies can vary based on changing premium prices in the market. If your subsidy is too high, you’ll have to pay it back at tax time.

States running their own exchanges will make individual decisions about how they are handling automatic reenrollment.

Consumers will have until Jan. 31 to sign up, but if you want your coverage to renew or begin by Jan. 1, you’ll have to complete your application by Dec. 15.

Some plans that were available last year may not be offered for 2016 because the health insurer decided not to sell the policy again. Some nonprofit insurers created by the health law – known as co-ops — have closed due to financial problems. Also, in some states, officials barred health plans that had been in effect before the health law but did not cover the law’s mandated benefits. In other states, federal rules allow these policies to continue through 2017.

I want to buy health insurance but can’t afford it. What should I do?

Depending on your income, you might be eligible for Medicaid, the federal-state program for low-income people. Before the health law, nonelderly adults without children didn’t qualify for Medicaid in most states. But now, states have an option to let the federal government pay the cost of an expansion in the program so that anyone with an income at or lower than 138 percent of the federal poverty level, (about $16,242 for an individual or $33,465 for a family of four based on current guidelines) will be eligible. So far, 30 states and the District of Columbia have chosen to expand Medicaid.

What if I make too much money to qualify for Medicaid but still can’t afford to buy coverage?

You might be eligible for government subsidies to help you pay for private insurance sold in the insurance marketplaces.

If your state has expanded Medicaid and you earn up to the 138 percent of the federal poverty line and need health insurance, you must enroll in Medicaid and cannot qualify for the law’s financial assistance to pay premiums and to help with out-of-pocket costs. In states that did not expand Medicaid, premium subsidies are available for qualifying individuals and families that earn between 100 and 400 percent of the poverty level, or about $11,770 to $47,080 for individuals and $24,250 to $97,000 for a family of four (based on current guidelines).

The subsidies are pegged to the federal poverty level and are most generous for those who make the least amount of money. They also require some individuals to spend a certain percentage of their income before the subsidies kick in.

I didn’t get health insurance in 2015. What is going to happen to me now?

When you file your income taxes for 2015, you’ll be asked whether you have health insurance. Unless you qualify for an exemption, if you don’t have coverage you’ll have to pay a penalty of the larger of $325 per person or 2 percent of income. In 2016, the penalty for not getting coverage will rise to the larger of $695 or 2.5 percent of income above the tax filing threshold of $10,150 for an individual.

What if I have health problems?

Insurers are no longer allowed to deny you coverage or charge you more based on a pre-existing medical condition. The law also eliminated annual and lifetime caps on coverage of essential health benefits, which include prescription drugs and hospitalization.

I get health coverage at work and want to keep my current plan.  Can I do that?

If you qualify for employer-provided coverage, you can stay in that plan, and that coverage is separate from exchange coverage that other consumers buy. But, just as before the law was passed, your employer is not obligated to keep your current plan and may change premiums, deductibles, co-pays and network coverage. Insurers can also change the plans they offer, so your employer may not be able to purchase the same plan it did a year ago.  If you have health insurance through work, you likely won’t qualify for a subsidy to purchase coverage on the exchange but there are exceptions.

I own a business. Will I have to buy health insurance for my workers?

No employer is required to provide insurance, but large employers who don’t could face penalties.

Starting in 2016, businesses with 50 or more employees that don’t provide health care coverage and have at least one full-time employee (those who work at least 30 hours per week) who receives subsidized coverage in the health insurance exchange will have to pay a fee of $2,160 per full-time employee. The firm’s first 30 workers would be excluded from the fee. Employers will have to cover 95 percent workers starting in 2016. Firms with fewer than 50 people don’t face any penalties.

What other parts of the health law are now in place?

You are likely to be eligible for some preventive services, such as blood pressure screenings and cholesterol tests, with no out-of-pocket costs.

Health plans can’t cancel your coverage if you get sick – a practice known as “rescission” – unless you committed fraud when you applied for coverage.

And, yes, children up to age 26 can still stay on their parents’ insurance. This has been one of the most popular provisions of the law.

Some plans that were in place when the law was passed and have not changed significantly do not have to abide by certain parts of the law. For example, these “grandfathered plans” can still charge beneficiaries part of the cost of preventive services.

Most plans are expected to change over time and lose grandfathered status.