After going through MEPS at entry level, continue advancing by 1. taking and passing the annual (mandatory) Advancement Exam - must score significantly higher than piers of the same job and class, and 2. Receiving high marks on cumulative job performance over the year. Plenty of bias and favoritism involved in #2, a highly subjective review by the direct, and greater chain of command. POs are ranked against each other comparing job importance and performance, and extracurricular duties that serve the military and Command. It takes a significant investment of personal time outside of job hours to advance in the Navy, with many job fields only promoting a tiny percentage of the workforce (as low as 1-3%) year over year. Advancement essentially depends upon who you know, who knows you, how well you can play the politics, and how much personal/family time you have sacrificed.. Despite sustained stellar performance, there are NO guarantees.