Here's the answer to your question: How does Magellan handle Duplicate Claims?

Magellan adjudicates all eligible claims that are submitted to a paid or denied status. Should a claim be submitted that duplicates the same expense for the same member as one that has been previously paid, Magellan will deny that claim indicating that the charge for the service was previously submitted and processed. No additional payment will be made.

Duplicate submissions of previously denied claims are reconsidered to determine if the original denial reason is still applicable. If the denial is still applicable, the claim will be denied indicating that the charge for the service was previously submitted and processed. If the original denial reason is no longer applicable then the claim will be reconsidered for benefit payment.