Sales pitches show up in your inbox and in phone calls. You can see ads on radio and television. Low premiums and extra benefits are promised by these campaigns.

They work. The proportion of eligible Medicare beneficiaries who enroll in Medicare Advantage plans has gone up. Most of the beneficiaries will be Advantage plan participants.

The annual enroll period starts again. Beneficiaries can switch between Medicare Advantage and traditional Medicare during the month of December. There are differences between these approaches.

Jeannie Fuglesten Biniek is a policy analyst at the Kaiser Family Foundation and co-author of a recent literature review comparing Advantage and traditional Medicare.

According to Dr. Biniek, both Medicare Advantage and traditional Medicare beneficiaries reported that they were satisfied with their care.

The researchers found that Advantage plans performed better than others. It was found that beneficiaries were more likely to use preventive services. Advantage beneficiaries were more likely to have a doctor.

There were worse affordability problems for traditional Medicare beneficiaries if they didn't have supplemental Medigap policies. They used high-quality hospitals more often.

Shopping or shifting between the programs has not been caused by any of the differences. Dozens of lawsuits accusing Medicare Advantage insurers of faking profits have not made much difference to consumers.

Consumers can compare the plans to find the best one for them. Three in 10 Medicare beneficiaries will compare their current plans in 2020, according to a survey.

The task of trying to evaluate the pluses and minuses may be daunting. The average beneficiary will be able to choose from 38 Advantage plans.

The health and financial consequences of Medicare Advantage and traditional Medicare are not the same.

Simple plans are offered by advantage plans. The doctor said it was one-stop shopping. You don't need a separate supplemental policy if you have your drug plan included.

Many plans have low or no monthly premiums. Out-of-pocket expenses are capped by Advantage plans. With the kind of plan that allows participants to use out-of-network providers at higher costs, beneficiaries will pay no more than $8,300 in in-network expenses.

Only a small percentage of Advantage plans allow that. The Center for Medicare Advocacy says that most plans operate like an H.M.O.

There are benefits that traditional Medicare can't offer. The most popular are vision, dental, and hearing.

The scope of the benefits should be looked at. Everyone in the plan can be limited or not. One cleaning may or may not be covered by dental care. Most Advantage enrollees pay their dental, vision or hearing costs out of pocket.

There are no networks when it comes to traditional Medicare. You can use any hospital or clinic that accepts Medicare.

The delays and frustrations of "prior authorization" are avoided by traditional Medicare patients. This advance approval is required for many procedures.

If your doctor says you need more care in a hospital or nursing home, the plan says, "No, five days, or a week, or two weeks, is fine" Either the patient pays out of pocket or forgos care.

Advantage participants who are denied care can appeal; when they do, the plans reverse their denials 75 percent of the time. Only a small percentage of beneficiaries or providers file appeals, which means there is a lot of necessary care missing from the program.

The Office of Inspector General found that 13 percent of services denied by Advantage plans would have been approved under traditional Medicare.

Changing from traditional Medicare to Advantage requires a major caveat.

Traditional Medicare doesn't have a cap on out-of-pocket expenses, so the co-pay can add up quickly. Most beneficiaries rely on supplemental insurance, also known as Medigap policies, to cover those costs, either they buy a policy or they have supplementary coverage through an employer or Medicaid.

There are people who leave traditional Medicare for Medicare Advantage plans. Insurers may deny Medigap applications or charge high prices if they want to return to traditional Medicare.

Mr. Lipschutz said that many people think they can try out Medicare Advantage for a while. He said that it is one type of insurance that can discriminate against you based on your health.

Data from millions of people has been used to track the differences between original Medicare and Medicare Advantage.

Advantage beneficiaries are less likely to go to the highest quality hospitals, less likely to be admitted to the highest quality nursing homes and less likely to use the highest rated cancer centers.

Patients with high needs were more likely to switch to traditional Medicare than those with low needs.

What happened to that? When you are healthy, you can run into less of the limitations of networks. You come up against more complex needs more often.

It can be hard for knowledgeable consumers to figure out which type of Medicare is better for them. Doctors and hospitals that are in-network this year might not be in the network next year. Drug formularies don't always stay the same. Deceptive marketing and advertising practices were documented in a new Senate report.

Trained volunteers from the State Health Insurance Assistance Programs can help people evaluate Medicare and drug plans.

The state programs don't have an interest in your decision making. At this time of year, their appointments fill up quickly. Don't waste time.