When is Pre-judgment Interest permissible in Legal Malpractice cases?  The Second Department recently wrote on this issue in Barnett v Schwartz ,2007 NY Slip Op 09712 ,Decided on December 11, 2007 ,Appellate Division, Second Department ,Ritter, J., J

"The plaintiffs are entitled to an award of prejudgment interest. "CPLR 5001 operates to permit an award of prejudgment interest from the date of accrual of the malpractice action in actions seeking damages for attorney malpractice" (Horstmann v Nicholas J. Grasso, P.C., 210 AD2d 671; see also Rudolf v Shayne, Dachs, Stanisci, Corker & Sauer, 8 NY3d at 444 n 3; Meyer v Glynn, 278 AD2d 291; Butler v Brown, 180 AD2d 406). In relevant part, CPLR 5001(b) provides: "[I]nterest shall be computed from the earliest ascertainable date the cause of action existed, except that interest upon damages incurred thereafter shall be computed from the date incurred. Where such damages were incurred at various times, interest shall be computed upon each item from the date it was incurred or upon all of the damages from a single reasonable intermediate date." Here, the earliest ascertainable date that the plaintiffs’ legal malpractice cause of action existed is December 21, 1992, the date that the agreement was entered into (see McCoy v Feinman, 99 NY2d 295; Town of Wallkill v Rosenstein, 40 AD3d 972). Thus, interest is to be computed from the dates that the damages were incurred (i.e., the dates that the plaintiffs paid the amounts awarded as damages for rent, renovations, and legal fees) or, if impractical, from a single reasonable intermediate date. "