(a) The contractor and HHSC may agree to mediate the dispute at any time before the 120th day after HHSC receives a notice of claim of breach of contract, or before the expiration of any extension agreed to by the parties in writing.(b) A contractor and HHSC may mediate the dispute even after the case has been referred to the State Office of Administrative Hearings (SOAH) for a contested case. SOAH may also refer a contested case for mediation pursuant to its own rules and guidelines, whether or not the parties have previously attempted mediation.