The attorney-client privilege lasts forever, but courts debate the duration of the work product protection.
In Maldonado v. New Jersey, 225 F.R.D. 120, 131 (D.N.J. 2004), the court noted this debate, explaining that “[m]ost courts” extend the protection to later litigation. The court also quoted Third Circuit dicta indicating that the protection only applies in “subsequent litigation which is ‘closely related'” to the litigation in which the litigant created the work product. Id. (citation omitted). Because of this dicta, the court apparently felt compelled to find (as a factual matter) that the current litigation was “closely related” to litigation in which the work product was created – thus assuring its continued protection. Id.
The debate over the work product doctrine’s duration highlights the differences between that protection and the attorney-client privilege, although it seems almost inevitable that work product normally would meet even this somewhat narrow standard – or else it would never be sought during discovery in the later litigation.