One of Bend’s largest private employers is getting bigger, spurred by a rapid increase in new Medicare Advantage customers.

PacificSource Health Plans, formerly Clear One Health Plans, announced Monday it has added 16 new employees at its Bend office, increasing the total workforce there to 160.

The company manages private insurance, Medicare and Medicaid programs for customers in Oregon, Idaho and Montana.

Medicare Advantage programs offer private insurance packages, with costs and services contracted out by the traditional Medicare program.

The company added 16,000 new customers during its recently completed Medicare Advantage enrollment period.

The new clients make up nearly 6 percent of PacificSource’s total client base, according to figures from a news release issued Monday by the company.

“This year’s growth is really evidence that PacificSource is gaining its share of the Medicare Advantage market,” company spokeswoman Colleen Thompson said.

Several factors have driven up Medicare Advantage enrollment nationwide.

Projected cost savings to consumers from the Patient Protection and Affordable Care Act led to a 28 percent increase in Medicare Advantage enrollment from 2010 to 2012, U.S. Secretary of Health and Human Services Kathleen Sebelius said in September.

More simply, the baby boomer generation is rapidly approaching 65, Medicare’s eligibility age.

In a company news release, Dan Stevens, PacificSource Health Plans senior vice president of government programs, called the 16,000-Medicare customer increase “unprecedented growth (that) we saw on the Medicare side of our business in 2012.”

Headquartered in Eugene, PacificSource moved to Central Oregon in 2010 after acquiring Clear One Health Plans.

Clear One was founded in Bend as Central Oregon Independent Health Services in 1995, according to The Bulletin’s archives.

A group of doctors and hospital executives established it to bring more local control over how the region administered the Oregon Health Plan, which distributes Medicaid funds.

But the company, which changed its name to Clear One and went public in 2009, ran into trouble shortly thereafter, losing $2.1 million in the third quarter of the year after posting gains throughout the company’s history. It cut 25 positions by the end of 2009, according to The Bulletin’s archives.

PacificSource paid $46 million to acquire Clear One in early 2010.

The new Bend employees were hired following interviews at career fairs late last year, and recently wrapped up training, Thompson said.

The company’s 144 workers made PacificSource the 46th largest private employer in Central Oregon last year, according to figures from Economic Development for Central Oregon.