UnitedHealth, the Medicare Advantage provider with the most enrolled members of any company serving more than one state, ranked near the bottom of 30 multi-state providers in call center customer service in 2013.

That was among the findings in a HealthPocket analysis of government data on Medicare Advantage call center customer service. HealthPocket, a free website that compares and ranks health insurance plans, studied several major customer service categories tracked by the government: overall call center customer service, dropped calls, on-hold time and accuracy of information received.

The top five providers in overall customer service were:

1. HealthPartners, Inc.
2. Gundersen Lutheran Health System Inc.
3. Cambia Health Solutions, Inc.
4. Health Plan of the Upper Ohio Valley
5. University of Pittsburgh Medical Center

The bottom five companies (the first listed received the lowest customer service score) were:

1. Universal Health Care Group, Inc.
2. Health Net, Inc.
3. UnitedHealth Group, Inc.
4. WellCare Health Plans, Inc.
5. Munich American Holding Corporation

Overall, HealthPocket found, more than 15 percent of the Medicare Advantage companies examined failed to meet the government standards for customer service through a call center.