And so it begins again, the annual deluge of advertising for private Medicare Advantage plans (also known as Medicare Part C). The open Annual Enrollment Period for Medicare begins October 15th and continues through December 7th.

As noted in Forbes, “Advertisements for Medicare Advantage plans are pervasive during the Annual Enrollment Period.” Counting the mailbox overflows, the word “pervasive” seems inadequate.

“They can also make these plans seem tempting, with their myriad benefits and low premiums,” continued Forbes with this caution: “An Advantage plan could be the right plan for you, but it’s important to do your research and speak to a Medicare agent about your needs rather than hastily enrolling in a plan that sounds great in its TV commercial.”

Indeed, Medicare Advantage plans can be a dream come true for some, but a nightmare for others.

“Before enrolling in a Medicare Advantage Plan, find out if your regular doctor(s), health care providers and hospital accept that plan…. If you want to keep your same doctor(s) and use the same hospital you’ve always used DO NOT SIGN UP FOR THAT PLAN,” cautions the Mississippi Department of Insurance.

Few doctors and hospitals will speak publicly about Medicare Advantage problems. One who did was Dr. Kenneth Williams the CEO of Alliance HealthCare in Holly Springs. “They don’t want to reimburse for anything — deny, deny, deny,” he told NBC News last year. “They are taking over Medicare and they are taking advantage of elderly patients.”

In September, the American Hospital Association raised the issue of prior authorization denials with the Inspector General for the U.S. Department of Health and Human Services, writing, “Hospitals and health systems continue to experience inappropriate denials and delays in care for MA (Medicare Advantage) beneficiaries.”

Denial of coverage seems to be particularly serious for rehabilitation services. An American Medical Rehabilitation Providers Association member survey found that as many as 80% of patients referred to inpatient rehabilitation hospitals and units were denied access by their MA plans.

The Centers for Medicare and Medicaid Services tightened up rules for prior authorizations last year, particularly regarding the use of algorithms, but the hospital association responded that hospitals and health systems saw little to no change in Medicare Advantage organization practices. “Indeed, MA beneficiaries continue to face persistent delays and denials of medically appropriate post-acute services.”

Other issues cited with Medicare Advantage plans include large co-payments required prior to service, lack of access to network physicians while traveling, and hospital stay limits that differ from doctor recommendations.

All this to say buyer beware during this year’s enrollment period.

Crawford is a syndicated columnist from Jackson.