SONOMA COUNTY — The Marin-Sonoma IPA has joined with Health Net to provide Medicare Advantage plans for Sonoma County seniors in the wake of a coverage agreement between Sutter Health and UnitedHealthcare.

The agreement between Health Net and Marin-Sonoma IPA, which has nearly 600 physicians in its network across the two counties, enables the Novato-based  IPA to offer Health Net’s Medicare Advantage plans to patients who wish to utilize non-Sutter Health affiliated hospitals, including Sonoma Valley,  Santa Rosa Memorial, Petaluma Valley, Palm Drive and Healdsburg District hospitals.

“Health Net stepped up to assure our senior residents continue to have a choice of physicians and hospitals throughout Sonoma County,” said Joel Criste, chief executive officer of the Marin-Sonoma IPA.

In October, Sutter and Minnesota-based UnitedHealthcare announced an exclusive agreement for Sutter to be the network provider for some 78,000 Medicare beneficiaries in Sonoma County.

The agreement between Health Net and the Marin-Sonoma IPA is a direct result of that, with Marin-Sonoma IPA saying its arragenment allows patients in Sonoma County to keep their existing physicians that practice at non-Sutter affiliated facilities.

Approximately 500 Marin-Sonoma IPA patients currently have United Healthcare Medicare plans that excludes both facilities and physicians not affiliated with Sutter, according to Marcy Norenius, spokeswoman for the Marin-Sonoma IPA, which has expanded into Sonoma County over the last year.

Sarah Bearce, a spokeswoman for UnitedHealthcare, said it's not an either-or decision between the two providers. She said one of the two plans United and Sutter will offer in Sonoma County has a network of physicians beyond those affiliated with Sutter, including Annadel Medical Group, Northern California Medical Associates and other contracted physicians throughout the county.

Overall, in Sonoma County, more than 2,600 Medicare beneficiaries will have to change their Medicare Advantage plans, according to the Centers for Medicare and Medicaid Services. UnitedHealthCare's change will impact just over 1,100, and Anthem Blue Cross is withdrawing its Medicare Advantage plan, which will impact some 1,400 beneficiaries.

"We established the agreement with Sutter, and because of the details of the agreement, we then had to close one of our plans in Sonoma County," Ms. Bearce said. 

Anthem Spokesman Darrel Ng said the health plan discontinued its Medicare Advantage plan "after evaluating the changes to the benefits, the pricing and the regulatory approval needed to make this plan financially viable in 2012 and beyond."

He added that Anthem is expanding its Medicare Advantage Local PPO plan in 13 California counties, including Sonoma County.

Sonoma County has 79,025 Medicare beneficiaries, including over 29,000 in Medicare Advantage plans, according to CMS. Beneficiaries can change plans during open enrollment, which began Oct. 15 and ends Dec. 7.