In 1966, Beltrán was succeeded as President by Alberto Héber Usher. He was re-elected to the senate in 1966, and retired from politics following the coup by Juan María Bordaberry.
In 1987 he was appointed Ambassador to the Holy See.
The rivalry between the Uruguayan Blanco and Colorado parties was a feature of the country's history for more than a century, and, indeed, an intense part of Beltrán's family history. However, in the second round of the 1999 elections, the Blanco Beltrán publicly supported Colorado Jorge Batlle Ibáñez for the presidency against Tabaré Vazquez.