New Hampshire Expert Witness Rules: What Litigators Need to Know

Expert witnesses play a crucial role in New Hampshire civil litigation, particularly in complex cases involving medical malpractice, engineering, commercial disputes, and product liability. New Hampshire adheres to structured rules for expert disclosure and admissibility, closely tracking federal procedures in many respects. However, the state’s reliance on court-specific scheduling orders and its own judicial precedents makes compliance a matter of both precision and local familiarity.

Designation Requirements

New Hampshire does not require a formal motion to designate expert witnesses. Instead, experts are disclosed through discovery responses and in accordance with the court’s Structuring Order (New Hampshire’s version of a scheduling order), pursuant to New Hampshire Superior Court Civil Rule 26.

When disclosing a testifying expert, parties must provide:

• The expert’s identity and contact information
• The subject matter of the testimony
• A summary of opinions
• The basis and reasons for each opinion
• The expert’s qualifications, including prior testimony and publications
• Any written reports, if applicable

Failure to provide complete and timely disclosures can result in preclusion under Rule 37, particularly if the opposing party is prejudiced or surprised by the omission.

Expert Disclosure Process

Expert disclosures in New Hampshire are typically governed by the Structuring Conference Order, which sets key deadlines for:

• Disclosing plaintiff’s experts
• Disclosing defense experts
• Expert depositions
• Daubert or Dalton-style motions to exclude testimony

Under N.H. Super. Ct. Civ. Rule 26(b)(5), parties must disclose:

• A summary of opinions and conclusions
• The basis for each opinion, including facts and data relied upon
• Supporting documentation such as charts, graphs, publications, or calculations
• The expert’s curriculum vitae
• A list of prior expert testimony
• Compensation information

Although written reports are not always required, they are commonly exchanged in cases involving scientific, medical, or economic testimony. The court may compel production of full reports when warranted by the complexity of the expert’s analysis.

Required Declarations

Expert affidavits or declarations are not required as part of initial expert disclosure in New Hampshire. However, they are critical at the summary judgment stage. When a party seeks to prove or rebut an essential element through expert opinion, that party must submit a sworn affidavit or declaration that:

• Is made on personal knowledge
• Contains facts admissible in evidence
• Establishes the expert’s competence to testify on the issues presented

In medical malpractice actions, expert affidavits are generally required to survive motions to dismiss or for summary judgment. These affidavits must affirmatively state that the defendant deviated from the standard of care and that such deviation caused the injury.

Fees and Compensation

There is no statutory cap on expert witness compensation in New Hampshire. Expert fees are typically negotiated by counsel and must be reasonable in light of the expert’s qualifications and the scope of work.

When a party deposes an opposing expert, the deposing party must pay a reasonable fee for the expert’s time, consistent with Rule 26(b)(4)(C). Courts may resolve disputes over fee reasonableness based on the expert’s customary rate and the complexity of the case.

Discovery Scope and Limitations

Discovery of expert witnesses in New Hampshire is controlled by Rule 26(b)(5), which provides that:

• Parties may obtain detailed information about testifying experts
• Discovery includes opinions, methodologies, supporting materials, and prior testimony
• Depositions of experts are permitted after full disclosure

Discovery of consulting experts—those retained but not expected to testify—is permitted only upon a showing of exceptional circumstances, such as when the facts or opinions held by the consultant are otherwise unavailable.

Draft expert reports and communications between attorneys and testifying experts may be protected under the work-product doctrine, although facts and data considered by the expert are discoverable.

Admissibility Standards

New Hampshire follows a Daubert-style standard, formally adopted in State v. Dahood, 148 N.H. 723 (2002), and codified in Rule 702 of the New Hampshire Rules of Evidence. The trial court acts as a gatekeeper, assessing the reliability and relevance of expert testimony before admitting it.

Under Rule 702, expert testimony is admissible if:

1. The witness is qualified as an expert by knowledge, skill, experience, training, or education
2. The testimony is based on sufficient facts or data
3. The testimony is the product of reliable principles and methods
4. The expert has reliably applied the principles and methods to the facts of the case

Courts may conduct pretrial hearings to assess admissibility under this standard. In addition to Dahood, the New Hampshire Supreme Court has reaffirmed that speculative or unsupported expert opinions will not survive scrutiny, particularly where causation is contested.

Key Deadlines & Strategy Notes

Deadlines for expert disclosures and challenges are set in the court’s Structuring Order and are strictly enforced. While the timeline may vary by case and court, typical deadlines include:

• Plaintiff’s expert disclosures: 120 days before trial
• Defense expert disclosures: 60 days after plaintiff’s
• Rebuttal disclosures: 30 days before discovery closes
• Expert depositions: Must be completed before the close of discovery
• Motions to exclude experts: Due before final pretrial conference

In cases involving scientific, medical, or financial experts, early engagement is essential. Experts should be prepared to withstand Daubert scrutiny, and attorneys should ensure their disclosures clearly state the methodology and reasoning behind each opinion.

State-Specific Statutes & Local Rules

• N.H. Super. Ct. Civ. Rule 26(b)(5): Governs expert witness disclosure and discovery
• N.H. Super. Ct. Civ. Rule 37(c): Sanctions for failure to disclose
• N.H. Super. Ct. Civ. Rule 56(e): Affidavit requirements at summary judgment
• N.H. R. Evid. 702: Admissibility of expert testimony
• State v. Dahood, 148 N.H. 723 (2002): New Hampshire’s leading Daubert case

Attorneys should also review Superior Court Administrative Orders and any county-specific local rules, particularly in Hillsborough, Merrimack, and Rockingham Counties, where additional requirements may apply to expert discovery and motion practice.