Which States Require a Certificate or Affidavit of Merit in Medical Malpractice Lawsuits?

Medical malpractice litigation is subject to heightened procedural requirements in many jurisdictions. Among the most significant is the requirement to file a certificate or affidavit of merit, a document designed to confirm that a plaintiff’s claim has been reviewed and deemed legitimate by a qualified medical expert. This requirement acts as a gatekeeping function to deter baseless claims and ensure that only those supported by professional opinion proceed into discovery and litigation.

However, these requirements are not uniform. Some states mandate expert involvement through an affidavit signed under oath; others require only an attorney’s certification of consultation. Several states impose no such obligation at all. Attorneys must therefore understand where these requirements apply, what form they take, and when they must be satisfied, or risk procedural dismissal—even when the underlying claim is valid.

States That Require Certificates or Affidavits of Merit

As of 2025, 29 U.S. states have enacted statutes mandating some form of affidavit or certificate of merit in medical malpractice lawsuits. These requirements vary in structure, content, and deadline. The following is a representative list of those states, categorized by the type of filing required:

Affidavit of Merit States

These jurisdictions typically require a sworn affidavit from a qualified medical expert stating that the care provided fell below the accepted standard and caused harm.

• New Jersey (N.J. Rev. Stat. §2A:53A-27)
• Illinois (735 ILCS 5/2-622)
• Nevada (Nev. Rev. Stat. §41A.071)
• Minnesota (Minn. Stat. §145.682)
• Mississippi (Miss. Code Ann. §11-1-58)
• West Virginia (W. Va. Code §55-7B-6)
• Wyoming (Wyo. Stat. §9-2-151)

These states require the affiant to be a physician or healthcare provider familiar with the applicable standard of care, often with recent or ongoing clinical experience in the same specialty.

Certificate of Merit States

In these jurisdictions, the certificate is usually filed by the attorney, confirming that a consultation with a qualified expert has occurred and that the expert believes the claim has merit.

• California (no statute, but case law supports pre-suit vetting)
• Pennsylvania (Pa. R. Civ. P. 1042.3)
• Ohio (Ohio R. Civ. P. 10)
• South Carolina (S.C. Code Ann. §15-36-100)
• Texas (Tex. Civ. Prac. & Rem. Code §74.351)
• Georgia (Ga. Code §9-11-9.1)
• Maryland (Md. Cts. & Jud. Proc. Code §3-2A-04)
• Michigan (Mich. Comp. Laws §600.2912d)
• Florida (Fla. Stat. §766.104)
• Connecticut (Conn. Gen. Stat. §52-190a)

While the certificate in these states often does not require notarization or inclusion of the full expert opinion, it still functions as a significant procedural step that can result in dismissal if not satisfied within statutory deadlines.

Hybrid States

Some states have unique or hybrid requirements that incorporate elements of both affidavits and certificates.

• Arizona (Ariz. Rev. Stat. §12-2603): Requires a preliminary expert opinion affidavit outlining factual bases for standard of care violations.
• Colorado (Colo. Rev. Stat. §13-20-602): Mandates a certificate of review by counsel affirming expert consultation within 60 days of filing.
• New York (CPLR §3012-a): Requires a certificate from the attorney stating they consulted with at least one expert.

In these states, timing and specificity requirements may vary, and courts expect strict adherence.

States That Do Not Require a Certificate or Affidavit of Merit

Roughly 21 states and the District of Columbia do not have a formal statutory requirement for a certificate or affidavit of merit. However, this does not mean plaintiffs are free from pre-suit scrutiny. Courts in these states may still expect that cases are filed in good faith and supported by expert testimony during litigation.

States without a formal merit requirement include:

• Alaska
• Massachusetts
• Oregon
• Rhode Island
• Vermont
• Washington, D.C.

While these jurisdictions offer more procedural flexibility, strategic prudence often dictates early expert involvement regardless of statutory obligation.

Timing Requirements by State

When certificates or affidavits are required, deadlines for filing vary widely:

• With the complaint: Nevada, Illinois, Georgia
• Within 60 days of filing: Colorado, Maryland, New Jersey
• Within 120 days: Texas
• Before trial or discovery: Some states allow more flexible timing, so long as defendants are not prejudiced

These variations can dramatically affect litigation strategy, especially in multi-jurisdictional cases or claims involving multiple defendants.

Expert Qualifications Also Vary

States impose different standards regarding who may sign a certificate or affidavit. Common requirements include:

• Licensure in the same profession or specialty
• Active clinical practice within the past 3–5 years
• Board certification in the same or similar field
• Experience teaching or supervising in an accredited medical program

Some jurisdictions also restrict experts with disciplinary histories or those who spend the majority of their time testifying rather than practicing.

Attorneys must ensure their selected expert meets state-specific criteria, or risk exclusion of the affidavit and subsequent case dismissal.

Practical Implications for Legal Strategy

Failing to comply with a state’s merit requirement is not a harmless error. In most jurisdictions, courts treat it as a jurisdictional prerequisite. Common sanctions for non-compliance include:

• Dismissal with prejudice
• Barring of expert testimony
• Tolling limitations denied

Moreover, some courts impose costs and fees on plaintiffs who fail to comply with affidavit statutes, even if the underlying claim has potential merit.

For attorneys managing cases in states with these requirements, early retention of a qualified expert and diligent review of applicable statutes is essential. Firms frequently partner with legal consulting services to navigate these requirements efficiently.

How Expert Institute Assists Attorneys

Given the diversity of rules across jurisdictions, Expert Institute offers specialized support in sourcing and vetting experts who meet precise statutory thresholds.

• Reviewing the claim and medical records
• Matching with experts qualified under state law
• Assisting with affidavit or certificate drafting
• Ensuring procedural deadlines are met

This comprehensive approach minimizes procedural risks and positions a claim for successful advancement.

Conclusion

More than half of U.S. states require plaintiffs in medical malpractice actions to file a certificate or affidavit of merit, each with its own procedural rules. Knowing where these requirements apply, and complying precisely with the applicable deadlines and expert qualifications, is essential to surviving early procedural challenges.

Attorneys practicing in multiple jurisdictions—or evaluating a complex claim with time-sensitive components—must be especially cautious. When properly managed, affidavits and certificates of merit can serve not only as compliance documents, but as strategic tools that enhance the strength and credibility of a case from its inception.