Additionally, due to their choices, eHealth estimated that 42 percent of Medicare customers would fall into Medicare’s coverage donut hole in 2014. Had people consistently selected the lowest cost prescription drug plan option, only 19 percent would have hit the hole.

Other findings from the eHealth analysis:

• 11 percent of MA-PD plan enrollees who used eHealth’s plan comparison tool were in the lowest cost plan. Potential 2014 savings had they switched to the lowest cost plan: $218.
• 3 percent of those in standalone PDPs were in the lowest-cost plan. Potential savings had they switched: $961.
• 58 percent of all consumers in the study would avoid the Medicare donut hole if they simply maintained their 2013 plan choices into 2014. Had they switched to the lowest cost plan in 2014, 81 percent would have avoid the donut hole.

One good sign revealed by the data: Consumers were searching for generic (usually less expensive) versions of brand name prescription drugs using the online tools. Top 10 searches for the following generics:

1. Omeprazole DR, a generic version of Prilosec, commonly used to treat gastroesophageal reflux disease (GERD)
2. Amlodipine Besylate, a generic version of Norvasc, commonly used to treat high blood pressure
3. Simvastatin, a generic version of Zocor, commonly used to treat high cholesterol
4. Clopidogrel, a generic version of Plavix, commonly used to treat coronary artery disease
5. Metformin, a generic version of Glucophage, commonly used to treat type II diabetes
6. Tamsulosin, a generic version of Flomax, commonly used to treat symptoms of enlarged prostate
7. Hydrochlorothiazide, a generic version of Dyazide, commonly used to treat hypertension
8. Fluticasone, a generic version of Flonase, commonly used to treat asthma and allergic rhinitis
9. Atorvastatin, a generic version of Lipitor, commonly used to treat high cholesterol
10. Hydrochlorothiadize, a generic version of Norvasc, commonly used to treat high blood pressure

“The price a Medicare beneficiary pays for his or her prescription drugs can change significantly because many Medicare prescription drug plans change the pricing, benefit tiers and formularies of their drug plans from year to year,” eHealth noted. “Any one of these changes may affect what an enrollee pays out of pocket for his or her drugs on the same PDP or MA-PD from one year to the next. In some cases, the lowest-cost plan for an enrollee's personal drug regimen in one year may not be the lowest-cost plan in the following year.”