Project Lazarus, also known as the Lazarus Project or simply Lazarus, was a Cerberus scientific project spearheaded by Miranda Lawson and Albert Wilson to perform at Lazarus Station by the ad-hoc Lazarus Cell at the behest of the Illusive Man. The sole aim of the project was to resurrect Commander Shepard, who had died when the SSV Normandy was attacked and destroyed over Alchera on 14 August 2183 CE by the Collectors. Without Shepard, the Illusive Man believed the Reaper threat would continue to be left unchecked, and that he represented the galaxy's main and only chance for dealing with the coming invasion, and with the Collectors beginning to abduct human colonies not long after Shepard's death, the Illusive Man knew something had to be done, so he addressed a concept previously dismissed as scientifically impossible: bringing Shepard back from the dead. Significant resources were pooled into the project, which the Illusive Man fittingly termed "Lazarus" (named for biblical figure Lazarus of Bethany), with an entire space station cleared for the operation and named after the project, and an entirely new cell formed for the sole purpose of working on the project, also named Lazarus. The project would prove to be one of Cerberus' most expensive projects ever conducted, with a total of four billion credits invested by 2185 CE. The goal of the project was to bring back Shepard as he originally was, and it was deemed that if Shepard was different in anyway, including morals and behavior, the project would have failed. Of course, just the act of resurrecting the man was going to be a massive hurdle on its own.

The project officially began in late 2183 CE, with Miranda Lawson assigned as project director and head of the Lazarus Cell while Albert Wilson was the chief medical officer. In the first few months of Project Lazarus, much of the work conducted was entirely research-based, as Cerberus was still in the process of fighting to retrieve Shepard's remains from the Shadow Broker, who planned to sell it to the Collectors. When Liara T'Soni, with Cerberus help, was successful in recovering the body, she handed it over to Cerberus, willing to risk it for the possibility that Shepard could return. With possession of the body, the project entered its development phase, lasting a year. The best medical and cybernetics experts from across Cerberus were brought in to work on the project, and the organization spared no expense in acquiring the best technology money could be, with the Illusive Man giving Lawson a blank check to get any and all resources she required to succeed.

Many methods were tried and failed: in the initial phases of the project, Miranda and Wilson toyed with the idea of using extracted DNA from Shepard's remains to create a functional clone of Shepard's body from the ground up, with a fully regrown clone of Shepard being made in just over a month: upon review however, Miranda submitted in her report to the Illusive Man that mimicking Shepard's exact neural pathways would be impossible with DNA alone, and that while Shepard's memories would be preserved, his personality would be totally unpredictable, and therefore uncontrollable: the Illusive Man deemed this unacceptable, and despite Miranda's insistence of using a control chip to counter this, the Illusive Man still deemed it a loss, and ordered the clone scrapped and to go back to the drawing board. Despite this, Miranda did not destroy the clone as ordered, with the second phase of the project utilizing organic reconstruction, and that the clone, already possessing a fully grown body, could be used to grow and harvest organs for use in the main subject quickly and easily: the Illusive Man approved this, so the clone was kept in a life support tank with just enough nutrients to keep it alive but not conscious. When operative Rasa was assigned to the Lazarus cell to sort out dossiers for potential recruits for Shepard's team when he woke up, she caught up a glimpse of the clone in storage and became enamoured with it: not long after, fed up with her life in Cerberus, Rasa defected, hacking the security mechs to create a distraction while she stole the clone and made her escape. Rasa later got the clone skin grafts to look like his twin and, two years later, helped it stage an attempt to kill the real Shepard and take over his life, an attempt that failed, with the clone dead and Rasa imprisoned.

Not long after the clone was abandoned, Miranda switched to simple organic reconstruction, although this too was ditched fairly quickly due to its scientific infeasibility, with Miranda coming up with the idea to utilize bio-synthetic fusion instead, with cybernetics utilized in the reconstruction of the body and allowing it to function: as these were perfected, Miranda implemented further improvements with the Illusive Man's approval, using cybernetics to make Shepard stronger and faster in combat. Upon transitioning to this new method, development significantly accelerated, with full muscular reconstruction completed by November 2184 CE, skin grafts completed and applied by January 2185 CE, and full revival projected by September: however, these projections were surprisingly proven wrong by Shepard's premature awakening in late July, accelerating the time table for his revival and proving Lazarus' success, much to the Illusive Man's satisfaction. Miranda once again suggested control chip, believing Shepard's idealistic altruism and hatred of Cerberus could prove an obstacle in their control over him, but the Illusive Man once again refused, believing it would only taint and limit Shepard's command abilities, which is what they resurrected him for in the first place. This decision, ironically, would ultimately prove to be Cerberus' undoing a year later at the end of the Reaper War.

Against all odds, Lazarus had succeeded, and Shepard was mostly ready by early August when he was abruptly awoken before his surgical scars could heal as a result of an attack on the station. Most of the Lazarus cell was killed and the station suffered extensive damage, largely as a result of Wilson revealing himself to be a traitor who orchestrated the attack by hacking the station's security mechs and turning them against their owners. Wilson was discovered and executed by Miranda for his actions, and the attack proved to be an excellent testing ground for Shepard, whose combat skills and personality were intact, further proving the project's success. With Shepard's escape from the station and returning to active service, Project Lazarus was declared complete and the Lazarus Cell officially dissolved, with Cerberus later returning to scuttle the station to prevent its access by outside parties, with the station written off as a loss due to extensive damage to the structure and its rapidly decaying orbit.