The litigation over New York University’s retirement plans is expanding to include the school’s hospital system and medical school, along with 21 individuals.

A new proposed class action, filed Nov. 13 in federal court (Sacerdote v. NYU Langone Hosps., S.D.N.Y., No. 1:17-cv-08834, complaint filed 11/13/17), names a host of new defendants and largely tracks the allegations made against the school in 2016, when six NYU employees sued the school over the fees and investment options in its retirement...