Hawaii Medical Service Association plans to discontinue its five Medicare Advantage plans for 46,000 seniors on Dec. 31.

The state’s largest health insurer, which covers the bulk of Hawaii’s Medicare population, estimates it lost about $64.1 million last year on its plans — called Akamai Advantage — due to higher-than- expected medical claims as well as lower federal Medicare reimbursements. 

The company will begin offering four new higher-premium plans in 2015 ranging from $70 and $126 a month on Oahu and $152 and $195 on the neighbor islands. HMSA currently has five Akamai Advantage plans with premiums ranging from zero to $91 a month.

HMSA said it is not changing its Medicare plans to save money, but to “better reflect the benefit needs and cost of caring for our members.”

AlohaCare announced last month that it also is ending its main Medicare Advantage health insurance plan in 2015, a move that will affect 1,300 senior members, after losses of $18.5 million since 2006.

Declining Medicare reimbursements, which typically do not cover the cost of medical services, have put a strain on health plans both locally and nationally. AlohaCare is paid a flat fee of $8,000 on average per member a year by the Centers for Medicare & Medicaid Services for the Medicare Advantage plan.

UnitedHealthcare and Kaiser Permanente Hawaii said there will be no significant changes to its Medicare Advantage plans. Ohana Health Plan said it will offer just two plans next year.