From the article (page 10):
There are a variety of reasons why physicians decide not to contract, or renew their contract, with health plans. For many, a reason to give up the benefit of patient “steerage” that comes with participating in a plan’s network is that the contractual rates for reimbursement are unfeasibly low. However, when physicians begin treating the plan’s members as an “out-of-network” provider, they often find that the plan’s reimbursement amount is not much higher, and may be even lower, than the plan’s contract rates. If you are seeing that trend in your practice, then it’s possible you are overlooking a few key steps that may help you get paid the amount you’re owed.