I divorce in 1988 my ex-spouse deceased in 2016 I never signed A QDRO. He remarried am I still entitled to any part of his pension

According to the information provided, it appears that you were married in 1976 and divorce in 1988 and in the divorce agreement, you either got no portion of your former spouse pension plan in the division of assets or the agreement was silent as to your entitlement to share in your former spouses pension plan. If this information is correct, then you have no claim or entitlement to share in the "marital portion" of his pension plan. For you to have an interest in his pension, the starting point would have been the divorce agreement. If the agreement did not provide for you to have a piece of that plan, then you would not have been entitled to a QDRO ( qualified domestic relations order) for a portion of the plan.