He graduated from Santa Rosa High School in 1988 and then entered the United States Naval Academy in Annapolis, Maryland.

He received his master's degree in National Security and Strategic Studies from the Naval War College in Newport, Rhode Island in 2007, and completed Nuclear Power School in Goose Creek, South Carolina in 2014.

[7] Crozier was designated a naval aviator in 1994 and was assigned as a Sikorsky SH-60 Seahawk pilot to the squadron HSL-37 at Barbers Point, Hawaii.

[8] In 2004, Crozier reported to Strike Fighter Squadron 94 (VFA-94), another F/A-18 Hornet unit known as the Mighty Shrikes, as a department head, and was again deployed with Nimitz in 2005.

The following year, he reported in 2007 to the Naval War College, where he earned a master's degree in National Security and Strategic Studies.

[8] From April 2014 until July 2016, Crozier completed the naval nuclear power training program and served as the executive officer of USS Ronald Reagan.

Crozier wanted to have most of the crew immediately taken ashore, saying it was impossible to prevent the spread of the virus in the close quarters of the ship.

[21] On April 1, the Navy ordered the aircraft carrier evacuated, with a skeleton crew to remain aboard to maintain the nuclear reactors, the fire-fighting equipment, and the galley.

[22][23][24] As he disembarked, sailors cheered him and chanted his name; videos of the scene were posted to Twitter and subsequently picked up by major news organizations.

[10] At a Pentagon news conference on April 3, Modly said that Crozier had "raised alarm bells unnecessarily" and showed "extremely poor judgment.

[20][29] In an April 4 interview with radio host Hugh Hewitt, Modly criticized Crozier's decision to send the letter to what he characterized as "a large list of other people," adding "And that, to me, just represented just extremely poor judgment, because once you do that in this digital era, you know that there is no way that you can control where that information's going to go.

"[33] Modly, Defense Secretary Mark Esper, and Chief of Naval Operations Admiral Michael Gilday each defended the decision to remove Crozier,[34][35] although Gilday and General Mark A. Milley, the chairman of the Joint Chiefs of Staff, had each advised Modly not to proceed until a Navy investigation into the matter had been completed.

[10] The investigation did not examine why the Theodore Roosevelt went ahead with the scheduled four-day port call in Da Nang, Vietnam, beginning on March 5, despite reported coronavirus cases in the country at that time, a decision that Navy officials defended.

[42] After the initial inquiry Gilday and the acting Secretary of the Navy, James E. McPherson, recommended on April 24 that Crozier be reinstated as captain of the Theodore Roosevelt.

In the interim, Crozier was reassigned to San Diego, where he served as the special assistant to the Naval Air Forces chief of staff.

Democratic senators Richard Blumenthal and Chris Van Hollen questioned the conclusion, saying that the Navy was retroactively applying current anti-COVID-19 best practices to a situation at the start of the pandemic to justify the dismissal.

He told Joe Garofoli of the San Francisco Chronicle: "The more time I've spent with family, friends—things outside of work—the better I could focus and the better I could perform at work.