Some states require an “affidavit of merit” in order for a plaintiff to bring a malpractice claim. The blog Professional Liability Matters has prepared this 50 state survey-table with the relevant information.
It is my understanding that typically these statutes refer to claims for "malpractice" while others mention the word "negligence." For this reason, there may some doubt as to whether a plaintiff bringing a claim
for a different cause of action, such as a breach of fiduciary duty or
an intentional tort, would be required to use of a certificate of merit.
The question is right now being litigated in New Jersey. Just a few days ago, in Perez v. Zagami, LLC, 2016 BL 7198, N.J. Super. Ct. App. Div., No. A-3268-14T2, 1/12/16, the court held that the New Jersey statute that requires malpractice plaintiffs to file an
affidavit of merit attesting to the viability of the complaint doesn't
apply to a lawsuit accusing an attorney of malicious use of process. Keep an eye on the case to see if the issue reaches the NJ Supreme Court. For more on the case go here.