Older Americans may be glad to know that Medicare generally will cover the cost of testing for the new coronavirus, or COVID-19. Yet getting a test isn't as simple as going to your local pharmacy or doctor's office and asking for one. "Lab services are covered by Medicare, but if someone wants a random test out of the blue, it wouldn't be covered if there's no medically necessary reason for it," said Jack Hoadley, a Medicare expert and analyst with Georgetown University's Health Policy Institute. However, Hoadley added, "in the current environment, if a doctor is concerned, they're going to say the test is medically necessary."

Travelers wear medical masks at Grand Central Station on March 5, 2020 in New York. David Dee Delgado

The number of COVID-19 cases in the U.S. has reached at least 755, with 26 deaths, according to a tally by Johns Hopkins University. Globally, more than 114,500 people have been infected, and at least 4,028 have died. The fast spread of the virus has wreaked havoc on the stock market as concerns of a global economic slowdown grow. Although the U.S. case count remains relatively low compared with some other nations, state and local governments are bracing for community outbreaks as the virus continues spreading. While many people experience mild symptoms from COVID-19, the virus appears to take a greater toll on individuals with underlying health conditions (i.e., a weakened immune system) and on older folks. That's similar to outcomes associated with the influenza virus, better known as the seasonal flu.

However, there is a flu vaccine, which is not the case for COVID-19 — that's probably a year away, if not longer. And, if the flu is caught early, it can be treated with antiviral medication that may lessen the symptoms and duration of the illness. There is no such option for this coronavirus. While the average risk of contracting COVID-19 remains low in the U.S., the country's top expert on infectious diseases has now warned people in high-risk groups to be cautious — especially if they are elderly and have an underlying medical condition. "No large crowds, no long trips and above all, don't get on a cruise ship," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in an interview Sunday on NBC's "Meet the Press." On Monday, the Centers for Disease Control and Prevention recommended that high-risk individuals stock up on supplies (such as extra medications and groceries), keep space between yourself and others, wash your hands often and avoid crowds. And, if there is an outbreak in your community, remain at home as much as possible.

In the current environment, if a doctor is concerned, they're going to say the test is medically necessary. Jack Hoadley Medicare expert and analyst with Georgetown University's Health Policy Institute

Symptoms of COVID-19 include fever, cough, shortness of breath and difficulty breathing. Severe cases can lead to pneumonia, severe acute respiratory syndrome, kidney failure and death, according to the World Health Organization. If you develop any symptoms that are concerning, you should contact your primary-care provider — by phone — for guidance. The CDC has encouraged providers to use their best judgment for who should be tested, which may be based on your symptoms or other factors such as known exposure to an infected person. If your doctor or other provider thinks you need testing, they'll contact their local health department or the CDC for instructions on where you can get the test, according to the National Institutes of Health. The test may involve a swab, blood draw or other method, depending on where the test is administered. The CDC said Monday that coronavirus testing is now available across all 50 states, with 75,000 lab kits total at public labs with more to come. Also, Quest Diagnostics and LabCorp — two of the country's largest private labs — are making test kits available. More from Personal Finance:

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Those market losses could help you save on taxes If you have a Medicare Advantage Plan and typically face a copay for a diagnostic test, major insurers have agreed to waive all copays on coronavirus testing, Vice President Mike Pence announced Tuesday at the White House. Some insurers previously have said they'd also waive any prior authorizations that normally would be required if a test is warranted. Additionally, Pence said that those insurers are expanding coverage of telemedicine, which could be helpful for people in vulnerable populations who may want to consult with medical professionals without having to go to a doctor's office. And, he said, there will be no "surprise billing," although additional details were not provided. Surprise billing generally happens when you go to an in-network facility (i.e., a hospital) but unknowingly receive services from out-of-network providers — which can result in large unexpected bills for the patient. Nevertheless, if there is a doctor's appointment involved in getting the test, you may have a copay or coinsurance, depending on your specific Medicare coverage. Costs beyond that would depend on whether you have the virus, whether you need additional medical treatment or should self-quarantine.