§15–1631.

    Except for an overpayment as defined in § 15–1629(h) of this subtitle, if a claim has been approved by a pharmacy benefits manager through adjudication, the pharmacy benefits manager may not retroactively deny or modify reimbursement to a pharmacy or pharmacist for the approved claim unless:

        (1)    the claim was fraudulent;

        (2)    the pharmacy or pharmacist had been reimbursed for the claim previously; or

        (3)    the services reimbursed were not rendered by the pharmacy or pharmacist.