Cortez is voiced by Mac Walters.
Cortez is the only child in his family and lost both of his parents years ago. He had a husband named Robert who was stationed at Ferris Fields in 2185, but the Collectors abducted the whole colony and Robert did not escape. While the Collectors were attacking, Robert called Steve, who was working on construction at a remote station not far from the colony, warning him to escape before the Collectors hit his station too. Steve begged Robert to escape with him, but Robert knew it was too late and asked Steve not to come after him, but to let him go and move on. Steve grieves heavily for his husband's death, and kept a recording of their last call.
He has been in the Alliance for about ten years, first serving in the First Fleet on-board the SSV Hawking piloting F-61 Tridents. According to him, he has a knack for procurements, but his skill set made him a more valuable person to command a flight deck.
Five months prior to the Reaper's invasion of Earth, Cortez was assigned to the Normandy SR-2 retrofit team, responsible for overseeing cargo bay modifications. His immediate task was to shift the Normandy's armory from its previous location behind the CIC to the shuttle bay.
Besides being a Kodiak pilot aboard the Normandy SR-2, he is also responsible for maintaining the Normandy's armory, a duty he shares with Lt. James Vega.
Cortez prefers to have as little time off from his duties as possible, since any time spent not working gives him too much time to think about Robert. Shepard has the option of convincing Cortez to take time off to leave the ship, visiting the Memorial Wall for victims of Collector and Reaper attacks at the Docks: Holding Area on the Citadel. Going there helps him to move on, and he meets up with some old pilot friends and forwards their information to Admiral Hackett, giving the Alliance some much needed pilots. A further encounter at Purgatory allows a male Shepard to begin a relationship with him.
During the final assault on Earth, after dropping off Shepard's squad, Cortez's shuttle is shot down by a Harvester. If he has been persuaded to visit the Memorial Wall, he will survive the crash. Otherwise, he cannot be contacted and James confirms Cortez's death later.
At some point, Cortez is seen in the Normandy's shuttle bay mourning Robert, his husband, who was taken by the Collectors. Shepard can comfort Steve by telling him that he's always there for him. Later, Shepard persuades Steve to take shore leave as a favor to the Commander. Cortez accepts the offer, replying that he finds it hard to say "no" to Shepard.
While Cortez is at the Citadel, he is seen at the Memorial Wall saying goodbye to his late husband. Shepard comforts him, commenting that Steve's past was his and that nobody could take that away. Cortez then thanks Shepard for his encouragement.
Eventually, Cortez will be in the Purgatory Bar. Shepard notes that Steve looks happier and Cortez replies that Shepard was right about the past being his, and that no moment should be taken for granted. When the Commander expresses doubt that a nightclub is to Cortez's taste, Steve explains that there was an energy and life in dancing, suggesting that the eye candy isn't too shabby for him either. Shepard wonders why Cortez isn't looking at him, though Cortez admits his interest and invites him to dance. While Cortez and Shepard dance, the Commander tells Cortez about his feelings, wanting to be more than friends. In reply, Cortez thought he felt there was something between them but was merely pessimistic about it. Shepard affirms that feeling and kisses Cortez.
Before the assault on the Cerberus Headquarters, Cortez visits Shepard to update him on the status of the armory and shuttle. He also tells Shepard he hopes he wants some company before the call is made to launch the assault. If Shepard accepts, the two kiss and spend the night together. Shepard can't sleep, anticipating the immense casualties of the assault and overwhelmed at the responsibility of the mission. Cortez comforts him, saying it was Shepard who managed to unite the whole galaxy.
Before the final battle on Earth, Shepard can contact a romanced Cortez via hologram after his shuttle crash. Glad he is unhurt, Shepard tells Cortez seeing the shuttle explode was a "feeling I never want to have again." Cortez admits it wasn't one of his finer moments as a shuttle pilot. He tells the Commander with him around, "the impossible doesn't seem that tough," and will be waiting for him after the war.