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Expert Witness Guides
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Expert witnesses in commercial arbitration may provide specialized financial, technical, scientific, or industry analysis, but their selection, disclosure, reporting, and testimony are governed by the arbitration agreement, applicable institutional rules, procedural orders, and governing law rather than automatically by federal court procedures. This article explains how AAA and JAMS rules address expert evidence, how attorneys can prepare reports and testimony, and what issues may arise involving disclosure deadlines, evidentiary disputes, subpoenas, and arbitral discretion.
Expert witnesses in arbitration provide specialized opinions on financial, technical, scientific, and industry-specific issues. Their analysis may help arbitrators evaluate disputed calculations, contractual performance, professional practices, and competing interpretations of evidence.
Unlike federal civil litigation, private commercial arbitration does not automatically follow the expert disclosure requirements of Federal Rule of Civil Procedure 26 or the admissibility standards of Federal Rule of Evidence 702. Expert selection, disclosure, reporting, and testimony depend on the arbitration agreement, applicable rules, procedural orders, and governing law.
This guide explains how attorneys can prepare and present expert evidence in U.S. commercial arbitration under the Commercial Arbitration Rules of the American Arbitration Association (AAA) and the JAMS Comprehensive Arbitration Rules. AAA expedited and large, complex procedures, as well as other JAMS rule sets, may impose different requirements.
The AAA and JAMS rules give arbitrators substantial authority over expert evidence, although their disclosure procedures differ.
AAA Commercial Arbitration Rule R-23 allows arbitrators to manage necessary information exchanges while protecting each party's opportunity to present its case. Expert witness disclosures and report schedules may also be addressed under Preliminary Hearing Procedure P-2(a)(xiii).
JAMS Comprehensive Arbitration Rules 17 and 20 establish requirements for exchanging information, identifying witnesses, and submitting pre-hearing materials.
AAA Rule R-35 and JAMS Rule 22 generally allow arbitrators to evaluate evidence without strictly following courtroom evidentiary rules. AAA Rule R-35(c) requires consideration of applicable legal privilege principles, while JAMS Rule 22(d) requires application of applicable law governing privileges and work product.
Selecting an arbitration expert witness requires matching the expert's specialized knowledge to the disputed issues.
Depending on the case, qualified professionals may examine:
Financial disputes: Forensic accountants may review transactions, financial statements, and accounting records.
Economic damages: Economists may calculate claimed lost profits or other financial losses using supported assumptions.
Construction disputes: Engineers and scheduling professionals may evaluate project delays, costs, and technical performance.
Business valuation disputes: Valuation professionals may estimate the value of a business, an ownership interest, or an intangible asset, including by assessing the financial projections used in the valuation.
Counsel should review the expert's qualifications, relevant experience, methodology, availability, and potential conflicts of interest before retention.
The expert's assignment should identify the technical questions requiring analysis without asking the expert to determine legal issues reserved for the arbitrator.
Alternative Dispute Resolution (ADR)
Dispute Resolution
Business Disputes
Contract Disputes
Expert witnesses in arbitration provide specialized opinions on financial, technical, scientific, and industry-specific issues. Their analysis may help arbitrators evaluate disputed calculations, contractual performance, professional practices, and competing interpretations of evidence.
Unlike federal civil litigation, private commercial arbitration does not automatically follow the expert disclosure requirements of Federal Rule of Civil Procedure 26 or the admissibility standards of Federal Rule of Evidence 702. Expert selection, disclosure, reporting, and testimony depend on the arbitration agreement, applicable rules, procedural orders, and governing law.
This guide explains how attorneys can prepare and present expert evidence in U.S. commercial arbitration under the Commercial Arbitration Rules of the American Arbitration Association (AAA) and the JAMS Comprehensive Arbitration Rules. AAA expedited and large, complex procedures, as well as other JAMS rule sets, may impose different requirements.
The AAA and JAMS rules give arbitrators substantial authority over expert evidence, although their disclosure procedures differ.
AAA Commercial Arbitration Rule R-23 allows arbitrators to manage necessary information exchanges while protecting each party's opportunity to present its case. Expert witness disclosures and report schedules may also be addressed under Preliminary Hearing Procedure P-2(a)(xiii).
JAMS Comprehensive Arbitration Rules 17 and 20 establish requirements for exchanging information, identifying witnesses, and submitting pre-hearing materials.
AAA Rule R-35 and JAMS Rule 22 generally allow arbitrators to evaluate evidence without strictly following courtroom evidentiary rules. AAA Rule R-35(c) requires consideration of applicable legal privilege principles, while JAMS Rule 22(d) requires application of applicable law governing privileges and work product.
Selecting an arbitration expert witness requires matching the expert's specialized knowledge to the disputed issues.
Depending on the case, qualified professionals may examine:
Financial disputes: Forensic accountants may review transactions, financial statements, and accounting records.
Economic damages: Economists may calculate claimed lost profits or other financial losses using supported assumptions.
Construction disputes: Engineers and scheduling professionals may evaluate project delays, costs, and technical performance.
Business valuation disputes: Valuation professionals may estimate the value of a business, an ownership interest, or an intangible asset, including by assessing the financial projections used in the valuation.
Counsel should review the expert's qualifications, relevant experience, methodology, availability, and potential conflicts of interest before retention.
The expert's assignment should identify the technical questions requiring analysis without asking the expert to determine legal issues reserved for the arbitrator.
Expert witness disclosure requirements depend on the applicable institutional rules and any scheduling orders.
The AAA Commercial Arbitration Rules do not establish a default deadline for exchanging expert reports. By contrast, Federal Rule of Civil Procedure 26(a)(2)(D) establishes default expert disclosure deadlines in federal civil litigation unless a court order or stipulation provides otherwise.
Under the AAA rules, the parties and arbitrator may establish deadlines for identifying experts and exchanging expert reports during preliminary proceedings, including any rebuttal submissions permitted by the procedural schedule.
AAA Rule R-24 authorizes arbitrators to enforce procedural orders. Under subsection (d), willful noncompliance with an arbitrator's order may lead to measures such as adverse inferences, exclusion of evidence, or special cost allocations.
Under JAMS Rule 17(a), parties must cooperate in good faith in exchanging relevant, nonprivileged documents and information immediately after arbitration begins. They generally must complete their initial exchange of relevant, nonprivileged documents and identify individuals they may call as witnesses within 21 calendar days after all pleadings or notices of claims have been received. The arbitrator may modify these requirements at the preliminary conference. Rule 17(c) also requires continuing supplementation, including the identification of additional experts as they become known.
Unless a scheduling order provides otherwise, JAMS Rule 20(a) requires parties to file with JAMS and serve and exchange specified materials at least 14 calendar days before the arbitration hearing. These include intended witness lists, descriptions of anticipated testimony with estimated direct-testimony durations, written expert reports that may be introduced, and lists of exhibits intended for use at the hearing. Parties should also exchange copies of intended exhibits that have not already been exchanged.
Under JAMS Rule 17(c), documents not previously exchanged and witnesses or experts not previously identified may not be considered at the hearing unless the parties agree or good cause is shown.
Although arbitration procedures may allow flexible report formats, a useful expert report ordinarily includes:
The expert's assignment and qualifications.
Relevant documents, records, and data reviewed.
Analytical methods and calculations.
Material assumptions and limitations.
Opinions supported by the analysis.
For example, an expert evaluating lost profits under a terminated distribution agreement may review historical revenue, operating expenses, sales trends, and market conditions.
The expert may estimate financial performance under a supported alternative scenario and compare it with actual results. The report should identify disputed assumptions and explain how alternative findings could affect the calculation.
Rebuttal reports may evaluate another expert's assumptions, calculations, or methods when permitted by the procedural schedule.
Expert testimony in arbitration may be presented through live questioning, written submissions, or authorized remote procedures.
AAA Rule R-33(a) provides for questioning by the arbitrator and opposing party. The arbitrator may vary the procedure while preserving each party's fair opportunity to present its case. Under AAA Rule R-33(c), the arbitrator may allow evidence to be presented by video, audio, or other electronic means. When witnesses testify that way, the other side must have an opportunity to cross-examine.
Under AAA Rule R-36(a), the parties must give written notice, by a date they agree on or the arbitrator orders, if they require an expert who provided a written witness statement to appear in person for examination at the hearing. If notice is given and the expert fails to appear, the arbitrator may disregard the witness statement, the expert report, or both, or issue another order considered just and reasonable.
During testimony, experts should be prepared to explain their methods, supporting records, material assumptions, and limitations. Arbitrators may ask questions directly to clarify technical findings or differences between competing opinions.
Counsel should raise disputes over late reports, missing records, witness availability, or expanded opinions promptly and document any objections in writing as required by the applicable rules and procedural orders.
Under Section 7 of the Federal Arbitration Act, 9 U.S.C. § 7, arbitrators within the statute's scope may summon witnesses to appear before them and, in appropriate cases, require them to bring material documents or records. Whether an arbitrator can compel a nonparty to produce documents before a hearing depends on the governing law. In Hay Group, Inc. v. E.B.S. Acquisition Corp., the Third Circuit held that Section 7 of the Federal Arbitration Act does not authorize documents-only subpoenas directed to nonparties before an arbitration hearing. The Eighth Circuit took a different view in In re Security Life Insurance Co. of America, 228 F.3d 865 (8th Cir. 2000), holding that Section 7 implicitly allows arbitrators to order the production of relevant documents before a hearing. The recipient there was a party to the contract underlying the dispute, and its status as a party to the arbitration was contested.
Under 9 U.S.C. § 10(a)(3), a federal court may vacate an arbitration award for arbitrator misconduct in refusing to postpone the hearing when sufficient cause is shown or in refusing to hear pertinent and material evidence, or for other misbehavior that prejudices a party's rights. In Tempo Shain Corp. v. Bertek, Inc., the Second Circuit vacated the district court's confirmation of an arbitration award and remanded the case after finding that the panel's refusal to continue the hearing to receive material testimony from a fact witness was fundamentally unfair under Section 10(a)(3) of the Federal Arbitration Act. Although the case did not involve expert testimony, it illustrates the limits on an arbitrator's discretion to exclude material evidence. Ordinary disagreements over evidentiary rulings do not automatically satisfy that standard.
Are expert reports required in every commercial arbitration?
No. Requirements depend on the arbitration agreement, applicable rules, and procedural orders. Some proceedings require written reports, while others permit different forms of expert evidence.
Does the Daubert standard apply to arbitration expert testimony?
Not automatically. The admissibility framework established in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), and reflected in Federal Rule of Evidence 702 does not ordinarily govern private commercial arbitration. Applicable requirements may incorporate that framework, however, and arbitrators may still consider reliability when evaluating expert evidence.
Are expert witness depositions permitted in arbitration?
They may be permitted, but they are not automatic. The availability and scope of expert depositions depend on the governing rules, party agreements, and arbitrator directions.
Can an arbitration expert supplement an earlier opinion?
Yes, when permitted under applicable disclosure requirements and procedural orders. Supplementation should be distinguished from introducing materially new opinions after the established deadline.
Expert witness disclosure requirements depend on the applicable institutional rules and any scheduling orders.
The AAA Commercial Arbitration Rules do not establish a default deadline for exchanging expert reports. By contrast, Federal Rule of Civil Procedure 26(a)(2)(D) establishes default expert disclosure deadlines in federal civil litigation unless a court order or stipulation provides otherwise.
Under the AAA rules, the parties and arbitrator may establish deadlines for identifying experts and exchanging expert reports during preliminary proceedings, including any rebuttal submissions permitted by the procedural schedule.
AAA Rule R-24 authorizes arbitrators to enforce procedural orders. Under subsection (d), willful noncompliance with an arbitrator's order may lead to measures such as adverse inferences, exclusion of evidence, or special cost allocations.
Under JAMS Rule 17(a), parties must cooperate in good faith in exchanging relevant, nonprivileged documents and information immediately after arbitration begins. They generally must complete their initial exchange of relevant, nonprivileged documents and identify individuals they may call as witnesses within 21 calendar days after all pleadings or notices of claims have been received. The arbitrator may modify these requirements at the preliminary conference. Rule 17(c) also requires continuing supplementation, including the identification of additional experts as they become known.
Unless a scheduling order provides otherwise, JAMS Rule 20(a) requires parties to file with JAMS and serve and exchange specified materials at least 14 calendar days before the arbitration hearing. These include intended witness lists, descriptions of anticipated testimony with estimated direct-testimony durations, written expert reports that may be introduced, and lists of exhibits intended for use at the hearing. Parties should also exchange copies of intended exhibits that have not already been exchanged.
Under JAMS Rule 17(c), documents not previously exchanged and witnesses or experts not previously identified may not be considered at the hearing unless the parties agree or good cause is shown.
Although arbitration procedures may allow flexible report formats, a useful expert report ordinarily includes:
The expert's assignment and qualifications.
Relevant documents, records, and data reviewed.
Analytical methods and calculations.
Material assumptions and limitations.
Opinions supported by the analysis.
For example, an expert evaluating lost profits under a terminated distribution agreement may review historical revenue, operating expenses, sales trends, and market conditions.
The expert may estimate financial performance under a supported alternative scenario and compare it with actual results. The report should identify disputed assumptions and explain how alternative findings could affect the calculation.
Rebuttal reports may evaluate another expert's assumptions, calculations, or methods when permitted by the procedural schedule.
Expert testimony in arbitration may be presented through live questioning, written submissions, or authorized remote procedures.
AAA Rule R-33(a) provides for questioning by the arbitrator and opposing party. The arbitrator may vary the procedure while preserving each party's fair opportunity to present its case. Under AAA Rule R-33(c), the arbitrator may allow evidence to be presented by video, audio, or other electronic means. When witnesses testify that way, the other side must have an opportunity to cross-examine.
Under AAA Rule R-36(a), the parties must give written notice, by a date they agree on or the arbitrator orders, if they require an expert who provided a written witness statement to appear in person for examination at the hearing. If notice is given and the expert fails to appear, the arbitrator may disregard the witness statement, the expert report, or both, or issue another order considered just and reasonable.
During testimony, experts should be prepared to explain their methods, supporting records, material assumptions, and limitations. Arbitrators may ask questions directly to clarify technical findings or differences between competing opinions.
Counsel should raise disputes over late reports, missing records, witness availability, or expanded opinions promptly and document any objections in writing as required by the applicable rules and procedural orders.
Under Section 7 of the Federal Arbitration Act, 9 U.S.C. § 7, arbitrators within the statute's scope may summon witnesses to appear before them and, in appropriate cases, require them to bring material documents or records. Whether an arbitrator can compel a nonparty to produce documents before a hearing depends on the governing law. In Hay Group, Inc. v. E.B.S. Acquisition Corp., the Third Circuit held that Section 7 of the Federal Arbitration Act does not authorize documents-only subpoenas directed to nonparties before an arbitration hearing. The Eighth Circuit took a different view in In re Security Life Insurance Co. of America, 228 F.3d 865 (8th Cir. 2000), holding that Section 7 implicitly allows arbitrators to order the production of relevant documents before a hearing. The recipient there was a party to the contract underlying the dispute, and its status as a party to the arbitration was contested.
Under 9 U.S.C. § 10(a)(3), a federal court may vacate an arbitration award for arbitrator misconduct in refusing to postpone the hearing when sufficient cause is shown or in refusing to hear pertinent and material evidence, or for other misbehavior that prejudices a party's rights. In Tempo Shain Corp. v. Bertek, Inc., the Second Circuit vacated the district court's confirmation of an arbitration award and remanded the case after finding that the panel's refusal to continue the hearing to receive material testimony from a fact witness was fundamentally unfair under Section 10(a)(3) of the Federal Arbitration Act. Although the case did not involve expert testimony, it illustrates the limits on an arbitrator's discretion to exclude material evidence. Ordinary disagreements over evidentiary rulings do not automatically satisfy that standard.
Are expert reports required in every commercial arbitration?
No. Requirements depend on the arbitration agreement, applicable rules, and procedural orders. Some proceedings require written reports, while others permit different forms of expert evidence.
Does the Daubert standard apply to arbitration expert testimony?
Not automatically. The admissibility framework established in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993), and reflected in Federal Rule of Evidence 702 does not ordinarily govern private commercial arbitration. Applicable requirements may incorporate that framework, however, and arbitrators may still consider reliability when evaluating expert evidence.
Are expert witness depositions permitted in arbitration?
They may be permitted, but they are not automatic. The availability and scope of expert depositions depend on the governing rules, party agreements, and arbitrator directions.
Can an arbitration expert supplement an earlier opinion?
Yes, when permitted under applicable disclosure requirements and procedural orders. Supplementation should be distinguished from introducing materially new opinions after the established deadline.
Alternative Dispute Resolution (ADR)
Dispute Resolution
Business Disputes
Contract Disputes
Expert Witness Guides
Expert Witness Guides