Is There an Obligation to Observe Yahrtzeit Year After Year, Even After Many Years Have Passed?

Greetings, There are those who say one should maintain all customs of the day of passing for fifty years from the date of death. Others hold that even after that period, one should continue the customs of the day of passing, including saying Kaddish and visiting the grave. See Chazon Ovadia, Aveilus, Part 3 (pages 337-339), which ruled that even after several decades, even fifty years from the date of death, one should persist in these customs to continue elevating the soul from strength to strength, from level to level in Gan Eden. See there for details. Bsorot Tovot, Hillel Meirs