Over the past two decades, this column has on three occasions addressed the issue of whether defendants may seek apportionment under CPLR Article 16 with respect to former defendants in the action who obtained merits based dismissals of the claims against them on summary judgment. It has been our steadfast position that such apportionment is prohibited by collateral estoppel and law of the case doctrine. It seems axiomatic that once a defendant has been adjudicated to be not liable as a matter of law, that finding is the law of the case, for all purposes. Nevertheless, efforts by defense counsel to defend their clients or limit their liability by blaming their former co-defendants continue to persist.

Our prior discussions of the subject identified several decisions which held that apportionment is not permitted in these circumstances, albeit not precisely as we have articulated. In the years since we last confronted this issue, however, the relevant appellate authority has recognized that defendants are collaterally estopped from attempting to place blame at trial on former defendants who were granted summary judgment. The evolution of this decisional law is the subject of this column.