This template is an expert retainer agreement that can be used to engage the services of an expert to assist a party engaged in a commercial litigation matter. This template includes practical guidance, drafting notes, and alternate and optional clauses. An expert can provide evaluative and consulting services in advance of and during litigation (a consulting or non-testifying expert), or more commonly, after litigation has commenced to provide opinion testimony in support of or in opposition to a party's claims at a trial or other legal proceeding such as arbitration (a testifying expert). This template can be used for either testifying or consulting experts, and is jurisdiction and industry neutral. It is usually prudent to retain the expert at an early stage of litigation, especially if the matter is complex and will require or benefit from expert participation. An early retention will, among other things, provide ample time for the expert to prepare necessary work product, and will allow the expert to participate in and help formulate discovery, case strategy, and participate in any alternative dispute resolution (such as mediation or arbitration) between the litigants. For more information on expert witnesses, see Expert Witnesses (Commercial Litigation); Commercial Dispute Avoidance and Management; Expert Witness Disclosures (Federal); Expert Reports (Federal); and Expert Retention Checklist (Federal). For additional guidance on services agreements in general, see Supply of Services and Supply of Services Agreements Resource Kit.