When Does a Priest Become a Monsignor?

When the bishop of a diocese believes that one of the priests under his authority should be honored for his exceptional service to the church, he can nominate that priest for the title of monsignor. The Pope reviews the nomination and makes the final decision.

What is a monsignor in the Catholic Church?

Monsignor, Italian Monsignore, a title of honour in the Roman Catholic Church, borne by persons of ecclesiastic rank and implying a distinction bestowed by the pope, either in conjunction with an office or merely titular.

What is the difference between a cardinal and a monsignor?

Unlike the rank of bishop or cardinal, and despite having distinctive garb and headgear, "Monsignor" is a form of address, not an appointment. Properly speaking, one cannot be "made a monsignor" or be "the monsignor of a parish".