Under St. Agnes Medical Center v. Pacificare of California (2003) 31 Cal.4th 1187, a court cannot hold that the defendant waived the contractual right to arbitrate solely by delayed assertion of that right, absence a showing of prejudice by the opposing party.  Here, defendant waited 13 months after plaintiff filed suit to move to compel arbitration and took plaintiff’s deposition and exchanged written discovery in the meanwhile.  Participation in litigation alone cannot support a finding of waiver, and fees and costs incurred in litigation alone will not establish prejudice.  As plaintiff showed no prejudice, the trial court erred in denying defendant’s motion to compel arbitration on the ground of waiver.