djplong is right. After years of struggling with a secondary coverage insurance company, we cut the cord with the employer-sponsored plan and went with a Medicare supplement. Here's how it used to go with the secondary company: "Your provider is out of network, so the deductible in $0,000. Dr. So and So is not in our network, so the copay is $000."

We went with a Medigap policy. Am not sure yet that it saves money over self-insurance but at least you know what they're going to pay. The particulars are covered by law, not what the insurance company does per their contract with the employer.