Connecticut Expert Witness Rules: What Litigators Need to Know

Connecticut’s expert witness rules offer a distinctive blend of common law tradition and procedural formalism. Attorneys navigating litigation in the state must be attuned to how experts are disclosed, challenged, and compensated under the Practice Book and relevant statutes. Mistakes—particularly with timing or content of disclosure—can lead to exclusion of critical testimony and potentially undermine the entire case.

Designation Requirements

Connecticut does not require a formal designation of expert witnesses in the manner that federal courts do. Instead, expert identity and opinions must be disclosed through discovery responses—most often via interrogatories.

Under Practice Book § 13-4, the following must be provided when disclosing experts:

• Name and address of each expert witness
• Subject matter on which the expert is expected to testify
• Substance of the facts and opinions to which the expert will testify
• Summary of grounds for each opinion

This requirement applies whether the expert is retained specifically for litigation or is an employee with relevant expertise. A court may preclude testimony if the disclosure is inadequate or not timely supplemented.

Expert Disclosure Process

Unlike jurisdictions that mandate expert reports, Connecticut relies primarily on written interrogatories for expert disclosure. This more streamlined approach places a premium on clear, comprehensive responses.

Key aspects of the disclosure process include:

• Use of standard interrogatories, such as Practice Book Form 220 for malpractice cases
• No automatic report requirement, unless ordered by the court
• Ongoing duty to supplement disclosures if the expert’s opinions evolve
• Court discretion to order depositions or further detail when fairness demands it

Because there is no uniform statewide deadline, disclosure timelines are dictated by case-specific scheduling orders or discovery cutoffs.

Required Declarations

While most civil cases do not require formal declarations at the time of expert disclosure, Connecticut law imposes a unique requirement in medical malpractice cases. Under Conn. Gen. Stat. § 52-190a, a plaintiff must attach to the complaint:

• A certificate of good faith
• A written opinion from a similar healthcare provider

This written opinion must articulate that there appears to be evidence of medical negligence. Courts may review the opinion in camera to determine its sufficiency, and dismissal is mandatory if the statutory requirements are not met. This rule serves as a preliminary gatekeeping function for medical liability suits.

Fees and Compensation

Connecticut does not set fixed rates for expert compensation, but the rules support payment for time spent preparing and testifying. Compensation is generally governed by agreement between counsel and the expert.

When opposing counsel takes the deposition of an expert, they are expected to:

• Pay a reasonable fee for the expert’s time at deposition
• Reimburse travel and related expenses
• Avoid excessive demands that would impose undue burden

If disputes arise, Practice Book § 13-4(c) allows the court to allocate or adjust compensation. In rare cases involving court-appointed experts, the court may establish fee limits based on funding constraints or equity.

Discovery Scope and Limitations

Expert discovery in Connecticut is narrower than in federal court. While interrogatory responses are required, expert depositions may not occur without either court approval or mutual agreement.

Limits include:

• No automatic right to depose an expert witness
• No obligation to produce draft reports or communications with counsel
• Court discretion to restrict, expand, or condition discovery on expert testimony

The court may grant a motion for deposition if the requesting party shows that written responses are insufficient for trial preparation. However, protections for mental impressions and attorney work product remain robust.

Admissibility Standards

Connecticut follows a Daubert-like standard for expert admissibility, established in State v. Porter, 241 Conn. 57 (1997). The Connecticut Code of Evidence § 7-2 requires that expert testimony:

• Assists the trier of fact
• Is based on sufficient facts or data
• Derives from reliable principles and methods
• Reflects a reliable application of those principles to the case

Trial judges act as gatekeepers, particularly with scientific or technical testimony. Non-scientific experts—such as those offering opinions based on experience—must still demonstrate relevance and reliability.

Key Deadlines & Strategy Notes

Connecticut does not impose a uniform deadline for expert disclosures. Deadlines are typically set by the court’s case management schedule or arise in response to discovery requests. Attorneys must carefully monitor these dates and respond promptly to interrogatories concerning expert opinions.

A failure to timely disclose expert information can result in preclusion, a serious penalty under Connecticut law. Courts have consistently enforced this remedy where nondisclosure prejudices opposing counsel or disrupts trial preparation.

Strategically, attorneys should consider the benefits of early expert disclosure to exert pressure in settlement discussions or demonstrate case readiness. Conversely, withholding expert details (within procedural boundaries) can retain strategic flexibility.

State-Specific Statutes & Local Rules

In addition to the Connecticut Practice Book and General Statutes, attorneys must be aware of judicial district-level rules or standing orders that govern scheduling, motion practice, and discovery timelines.

Relevant rules include:

• Practice Book § 13-4 (expert interrogatories and discovery)
• Conn. Gen. Stat. § 52-190a (good faith certificate in malpractice claims)
• Connecticut Code of Evidence §§ 7-2 through 7-4 (expert testimony standards)

Courts in larger judicial districts may issue individualized pretrial orders that further structure expert exchange. Additionally, the Connecticut Supreme Court and Appellate Court frequently interpret these rules in published opinions, shaping how they apply in practice.