Star Trek’s original USS Enterprise, led by Captain Christopher Pike (Jeffrey Hunter, Anson Mount) andCaptain James T. Kirk (William Shatner), has had four doctors serving as Chief Medical Officer. The Starship Enterprise is regularly assigned five-year missions of deep space exploration by 23rd century Starfleet. The physical, mental, and emotional health of the USS Enterprise’s crew, which consists of 200 to 400 souls, is the responsibility of the Chief Medical Officer.
Star Trekfans are accustomed to a particular doctor as the Chief Medical Officer of the Starship Enterprise. InStar Trek: The Next Generation, the CMO wasDr. Beverly Crusher(Gates McFadden), althoughDr. Katherine Pulaski (Diana Muldaur) replaced CrusherinTNGseason 2.Star Trek: Enterpriseonly had one Chief Medical Officer, Dr. Phlox (John Billingsley). However, the USS Enterprise NCC-1701, which had been in service since 2245, hadfour Chief Medical Officers at various points during Captain Pike and Captain Kirk’s commands.

4 Doctors Aboard Captain Pike & Kirk’s USS Enterprise Explained
The Starship Enterprise Rotates Chief Medical Officers
The Starship Enterprise’s four doctors are a result of the evolution ofStar Trekwhen it became an NBC TV seriesin the mid-1960s, and five decades later, when the prequelStar Trek: Strange New Worldswas created. Dr. Phil Boyce (John Hoyt) was the Enterprise’s first Chief Medical Officer. Boyce only appeared inStar Trek’s original pilot, “The Cage.” Boyce was replaced by Dr. Mark Piper (Paul Fix), who also made only one appearance inStar Trek: The Original Series' second pilot, “Where No Man Has Gone Before.”
Every Doctor On The Enterprise In Star Trek Ranked
Star Trek’s flagship USS Enterprise has featured plenty of physicians over the years, some of them more gifted and appealing characters than others.
Dr. Leonard McCoy (DeForest Kelley)became the Starship Enterprise’s Chief Medical Officer inStar Trek: The Original Series.John Hoyt’s Dr. Boyce was let go after NBC wantedStar Trek’s cast replaced for the second pilot episode ordered.Star Trekcreator Gene Roddenberry thought Paul Fix’s Dr. Piper was too old, andGene wanted DeForest Kelley cast asStar Trek’s Doctoralongside Captain Kirk and Mr. Spock (Leonard Nimoy).

Dr. M’Benga, played by Booker Bradshaw, also appeared as an expert on Vulcans in Star Trek: The Original Series.
Finally,Star Trek: Strange New Worldsintroduced Dr. Joseph M’Benga (Babs Olusanmokun), the USS Enterprise’s Chief Medical Officer in the years beforeStar Trek: The Original Seriesbegins. However, in terms of the order these physicians served on the EnterpriseinStar Trek’s timeline, it’s Dr. Boyce under Captain Pike (Jeffrey Hunter) in 2254, Dr. M’Benga from 2259 onwards under Captain Pike (Anson Mount), Dr. Piper under Captain Kirk briefly in 2265, and then Dr. McCoy under Captain Kirk from 2265 until 2293.

Nurse Chapel Becomes A Doctor After Star Trek: The Original Series
Nurse Christine Chapel is the primary nurse of the Starship EnterpriseinStar Trek: The Original Seriesand inStar Trek: Strange New Worlds. Nurse Chapel (Jess Bush) in her younger years onStrange New Worldsworks alongside Dr. M’Benga, with whom she has a history asveterans ofStar Trek: Discovery’s Klingon War. Nurse Chapel (Majel Barrett-Roddenberry) continues serving on the USS Enterprise inStar Trek: The Original Seriesunder Dr. Leonard McCoy.
Star Trek Waits Too Long For Nurse Chapel To Become Doctor
Strange New Worlds' Nurse Chapel served aboard the Enterprise from 2259 until finally becoming a Doctor in Star Trek: The Motion Picture. Here’s why.
Christine finally becomes Doctor Chapel inStar Trek: The Motion Picture, and she is the fifth physician to serve as Chief Medical Officer of the USS Enterprise. However, Admiral Kirk drafted a retired Dr. McCoy back into Starfleet and installed Bones as his CMO, a position McCoy retained for almost 20 more years, untilStar Trek VI: The Undiscovered Country.Still, Christine Chapel is the first to rise from nurse to doctor and Chief Medical Officer of the USS Enterprise inStar Trek.

Star Trek: The Original Series
Cast
Star Trek follows the U.S.S. Enterprise on its five-year mission to explore the galaxy, led by Captain James T. Kirk and First Officer Mr. Spock. The crew confronts a variety of challenges, including Klingons, Romulans, and genetic supermen, as they search for new life and civilizations.