MOUNTAIN VIEW, Calif. — Most people don’t include out-of-pocket costs for prescription drugs when comparing Medicare drug benefits, and far fewer beneficiaries will hit the "doughnut hole" coverage gap this year, according to research by eHealth Inc.

The online health insurance exchange said Wednesday that during Medicare’s 2013 annual enrollment period (AEP), just 22% of beneficiaries entered the names and dosages of prescription drugs they were taking while comparison shopping for Medicare Advantage Prescription Drug (MAPD) plans or stand-alone Medicare Prescription Drug Plans (PDPs) at eHealthMedicare.com or PlanPrescriber.com.

Specifically, eHealth’s analysis of 450,000-plus unique user sessions during the 2013 AEP found that fewer than 110,000 visitors used their prescribed medications to help them estimate the total cost of ownership for any of the plans available.

For those evaluating Part D coverage, it’s critical to assess the out-of-pocket costs for prescriptions because plans have different drug formularies or sets of Part D-approved drugs that they will cover, and the cost-sharing for covered drugs usually varies from plan to plan, eHealth noted. As a result, someone who enrolls in a plan that doesn’t cover the specific drugs they take would have to pay the full price for those medicines themselves.

A November 2012 study by Avalere Health( found that none of the top 10 Medicare drug plans covered 100% of Part D-approved medications, eHealth reported. The percentage of Part D-approved drugs covered by those plans ranged from 53% to 76%. The Avalere report also found that a beneficiary’s out-of-pocket costs for a prescribed medication ranged from as little as $1 for a preferred generic drug to as much as $95 for a nonpreferred brand medication, or 45% of the drug’s cost.

eHealth’s 2013 Medicare Choice & Impact Study also found that the average person, on at least one prescribed medication, would save an average of more than $1,200 in out-of-pocket costs in 2013 by enrolling in Part D coverage, either through a PDP or MAPD. In addition, the study revealed that the average person who entered the name of their current PDP or MAPD plan, as well as the specific drugs they were taking, would have saved over $600 in 2013 on their out-of-pocket prescription drug costs.

Meanwhile, another eHealth analysis showed that only 9% of Medicare beneficiaries will reach the doughnut hole coverage gap this year, down from the 33% that eHealth projected for the 2012 plan year.

Of users who will hit the coverage gap in 2013, 62% will do so between September and December in their current Medicare prescription drug plan.

The eHealth analysis reviewed over 17,000 unique user sessions from its eHealthMedicare.com and PlanPrescriber.com sites that occurred during the 2013 Medicare AEP, which ran from Oct. 15 to Dec. 7, 2012. Of the 17,000 sessions analyzed, over 11,000 were used to compare stand-alone Medicare PDPs, and over 6,000 were used to compare MAPD plans.