Since almost all Medicare enrollees (90 percent) choose plans with a drug benefit, there's a lot at stake for plan providers if the enrollees begin to make different choices than they have in the past. HealthPocket's research strongly suggests that those enrollees could be making smarter choices for themselves.

"Consumers will find that even with their medication on a plan's formulary they may still need to pass through hoops in order to get their prescription filled," HealthPocket said. "The plans are designed to keep costs down by monitoring utilization and creating carrots and sticks for consumers to gravitate toward the lowest cost form of medication that works for them. The hoops include:

• Quantity limits: The plan limits how much may be received at any one time.
• Prior authorization: A health care provider must contact the plan to explain why the prescription is medically necessary and get its prior approval.
• Step therapy: The enrollee needs to try a less expensive drug and have no success before he or she is allowed to move on to a more expensive drug.

While these hoops were created allegedly to contain costs, turns out they often do just the opposite. For instance, HealthPocket found that prior authorization alone — instead of automatic refill authorization — can be quite costly.

"A Kaiser Family Foundation study found that four drugs (Celebrex, Cymbalta, Nexium and Lyrica) had a prior authorization requirement for at least 10 percent of PDP enrollees. While designed as a cost saving measure, research also shows a high cost to implementing the plan restrictions. One study indicated a cost for prior authorization in the time taken to go through these steps to amount to $40.75 per incident."

HealthPocket reviewed formulary data for both the basic, or standalone, Medicare plan (Part D Prescription Drug plans) and the Advantage plan (Medicare Advantage Prescription Drug plans). Here are the hoops for each:

PDP plan's drugs:

• 17 percent had a quantity limit
• 18 percent had prior authorization
• 1.5 percent had step therapy

MAPD plan's drugs:

• 16 percent had a quantity limit
• 19 percent had prior authorization
• 2 percent had step therapy

There's one major exception to this trend toward hoop-building around prescription drugs: Kaiser.

"Kaiser plans had no quantity limits, no step therapy requirements, and only 3.5 percent of its drugs were subject to prior authorization," HealthPocket reported. "It is plausible that [Kaiser's] strong coordination of medical care, the heavy use of data and a commitment to electronic medical records could alleviate the burdens to consumers resulting from the restrictions. The Kaiser example is a cause for optimism that there may be workable alternative approaches to drug utilization management."

In conclusion, HealthPocket suggested Medicare eligible consumers confirm each year during the Medicare annual enrollment period that they enroll in a drug plan that "includes all of the drugs they take on that plan's formulary."

"Consumers also should confirm that their chosen plan doesn't include unreasonable obstacles to obtaining drugs that are on their formularies. The obstacles may amount to a slight inconvenience, or they may become time consuming and create a delay in receiving medication or require someone to start with a different drug," HealthPocket researchers said.