A method of preparing a polyurethane, polyurea, polycarbodiimide or polyisocyanurate polymer from a formulation including a delayed action catalyst comprising contacting as formulation components an active hydrogen-containing compound and a diisocyanate or polyisocyanate in the presence of a delayed action catalyst which is a tin(IV) salt complexed with a primary or secondary amine compound, under reaction conditions sufficient to form a polyurethane, polyurea, polycarbodiimide, or polyisocyanurate polymer.