Medical Expert Witness Restrictions Upheld in Maryland Part 1 reports on Maryland’s requirements for medical expert witnesses:

Maryland’s highest court upheld a tort reform measure requiring certain qualifications for expert witnesses in medical liability cases, a move physicians say will prevent plaintiffs from using so-called “hired guns” to bolster meritless lawsuits. The 2004 law prohibits the use of medical expert witnesses who devote more than 20% of their professional time to testifying in personal injury cases….
“This allows a qualified doctor to continue to utilize his or her expertise [to assist in medical liability cases], but prevents him or her from launching a second career as purely an expert witness,” states the opinion in University of Maryland Medical System v. Waldt (