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County Health Plans (CHP)

Anthem Blue Cross Logo

The County Health Plans (CHP) are self-funded, meaning the contributions from the County of Sonoma and eligible employees and retirees are used to pay plan benefits, including services provided to the members and claims administration. 

Anthem Blue Cross is the network provider and medical plan claims administrator for both the EPO and PPO plans. 

If you reside within California, services are provided through the Prudent Buyer Plan network (Blue Cross PPO Prudent Buyer - Large Group). Plan members have access to more than 60,800 doctors and specialists that make up a strong local California network. Anthem Blue Cross has contracted with more than 90% of hospitals in California, including 400 acute care hospitals. 

If you reside outside of California, services are provided through BlueCard network (National PPO Blue Card PPO). More than 96% of hospitals and more than 91% of physicians across the country contract with Anthem Blue Cross through the BlueCard® program.

Need help deciding which plan is best for you? For a side by side plan comparison of the CHP EPO and PPO plans view the Medical Plan Comparison Chart.

Effective June 1, 2024


Employees will no longer be eligible to enroll in a CHP plan effective June 1, 2024. Employees enrolled prior to June 1, 2024 will be grandfathered into the plan. Once an employee leaves a CHP plan, they will no longer be eligible to return to a CHP plan.  

Medicare Retirees

Retirees enrolled in Medicare will no longer be eligible to remain on a CHP plan effective June 1, 2024. Medicare retirees will need to elect another Medicare eligible plan. Available health plan providers with Medicare eligible plans include; Anthem Blue Cross, Kaiser Permanente, Western Health Advantage and UnitedHealthcare. 

Customer Service and Group Numbers

What is an EPO and PPO?

Prescription Coverage by CVS Caremark

CVS Caremark Logo

View the Performance Drug List for a list of covered prescription medications. This list is not all inclusive, can change at any time and does not guarantee coverage. 

If a generic drug is not available, you will pay the brand-name copay.

If a brand-name drug is medically necessary, as prescribed by your doctor, your doctor must request an exception to the plans’ mandatory generic policy through CVS/Caremark prior to getting the prescription filled. If approved, you will be charged the brand-name copay.

However, if you choose the brand-name drug, or the exception is not approved, the drug will be a covered expense and you will be responsible for the brand copay along with the difference between the brand and generic cost.

If you are taking a maintenance drug, it can be filled at any retail pharmacy twice. After the second fill, it must be filled at a CVS pharmacy or by mail order through CVS/Caremark.

A Formulary Exclusion List can be found by logging into your account on CVS/Caremark's website or by calling CVS/Caremark at 800-552-8159.