(CNN) As coronavirus cases multiply across the nation, many Americans who aren't feeling too well are worried about how much they'll have to pay to get checked out.

The answer isn't simple -- it depends on what insurance they have, where they seek care and what tests the doctor orders. This uncertainty may deter some folks from seeing a doctor, which could increase the disease's spread.

While there's been no charge for Centers for Disease Control and Prevention tests in public health labs, commercial labs and hospitals are developing their own screenings, which are expected to carry a fee.

"That means, by definition, it's covered in the private health insurance of every American, as well as covered by Medicare and Medicaid," he said.

Coverage, however, isn't the same as cost. Typically, it means that the test is considered part of one's benefits package, but it's still subject to deductibles and copays. Plus, many large employer plans are not subject to Affordable Care Act rules governing essential health benefits. Neither are certain other less comprehensive insurance products, such as short-term health plans

Several large insurers, including Cigna, Anthem and CVS' Aetna, have announced in recent days that they'll pick up the tab for the test ... but only for certain members.

Cigna and Anthem will waive any cost-sharing for tests for those in individual market plans, Medicare Advantage, Medicaid managed care and fully insured employer policies, in which the insurers pay the claims.

However, the move does not automatically extend to large-employer policies in which the companies pay the claims. About 61% of workers are covered by these self-insured plans, according to the Kaiser Family Foundation.

Aetna said it will waive copays for tests for all its policyholders, though self-insured employers can opt out. The carrier will also allow members to access telemedicine services at no charge for the next three months.

"Supporting the health and well-being of our members and removing barriers to care are among our key areas of focus as we navigate the spread of COVID-19," said Karen Lynch, Aetna's president, referring to the specific illness related to the coronavirus.

The Blue Cross Blue Shield Association announced Friday that its network of 36 independent Blue Cross and Blue Shield companies, which includes Anthem, will cover the costs of coronavirus diagnostic testing for members in individual, Medicare and fully insured employer plans.

Traditional Medicare , meanwhile, will also cover the test . There is typically no cost sharing on clinical diagnostic laboratory tests, according to the Centers for Medicare and Medicaid Services.

Medicaid benefits vary by state, but recipients typically pay little or nothing out of pocket for testing and services.

At least four states -- New York, Washington, Nevada and California -- announced this week that they are requiring certain insurers to waive copays for coronavirus screening and the visit to the medical provider. But again, this doesn't apply to large companies that are self-insured.

The roughly 27 million Americans who lack insurance, however, do not have any of these protections. They typically are cared for in community clinics, which often charge based on income, or in emergency rooms, which could leave them with big bills.

However, the coronavirus test is not the only charge patients may face. They will likely be responsible for the office visit and may have other tests done -- to make sure they don't have the flu, for instance. If they seek care in an emergency room, that probably will be much more expensive than going to a doctor's office or urgent care center or using telehealth.

And if they have coronavirus and are seriously ill, they may be hospitalized.

All these services and treatments will be subject to their deductibles and cost-sharing.