There are over 200,000 Catholic priests in the world today, and 2,946 Catholic bishops, according to the website Bible.ca. The role of the bishop is to oversee a network of priests and their parishes, also called a diocese. There are three positions of power in the Catholic church: priests, bishops and one pope. Because there are so few bishop positions relative to the number of priests in the world, becoming a bishop is not as easy as filling out an application.
Become a priest. This requires formal training, including a four year degree in theology. Once you complete your degree, you will spend anywhere between four and five years in a seminary, followed by work in the Catholic church as a deacon. A deacon is a layperson who assists the priest in a parish. Once you have completed this training, the bishop who oversees the parish where you have been assisting will ordain you as a priest.
Create a strong impression on the bishop who presides over your diocese. The bishops are the ones who are continuously watching the priests in their network to determine which of them are suited for nomination to become a bishop.
Wait for a bishop position to open. According to the Code of Canon Law, once a bishop reaches the age of 75, he must tender his resignation to the pope. A bishop position could also open up if a bishop becomes ill or dies before reaching age 75. Once a bishop position opens up, each of the current bishops will submit the names of priests in their diocese who they feel are suitable candidates to be ordained as a bishop. All of the names are then submitted to the archbishop who reviews the candidates and gathers all the bishops of his province to vote on their selection. These candidates then are passed to the Congregation for Bishops who attach their recommendations and send the final list of candidates to the pope for his final decision.
Accept the offer for the bishop position. Once the pope chooses you from the list of priests to become the next bishop, you will receive a formal offer for the appointment. Once you accept the offer to become bishop, a formal ceremony and official announcement is planned and the pope ordains you as a Catholic bishop.