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For the EMH from the USS Voyager, see: The Doctor.


The Emergency Medical Hologram or EMH is a sophisticated holographic program used upon Starfleet starships and facilities in the late 24th century to assist medical staff in times of emergency. The program whose formal name is EMH Program AK-1 Diagnostic and Surgical Subroutine Omega-323 was developed by Doctor Lewis Zimmerman on Jupiter Station.

EMHs are programmed with five million possible treatments from the collective information of 2000 medical references and the experience of 47 individual medical officers, as well as having adaptive programming for situations outside of those in their database. EMHs are only meant to be used a temporary measure to assist existing medical staff, or in extreme cases, to temporarily replace them until a new doctor is assigned.

Mark I[]

Work on the EMH program began as far back as the year 2360 which was conducted by Starfleet Medical, though information on it was known only to a few individuals.

Zimmerman's initial proposal for an Emergency Medical Hologram was presented in 2365 to Doctor Beverly Crusher, Chief medical officer of the USS Enterprise-D.

By the time the holographic matrix was completed in 2370, it had to have official approval by Leonard McCoy.

The Mark I EMH was modelled on Doctor Zimmerman, in both its physical characteristics and personality. This was considered a flaw in the program's design by many Starfleet medical personnel, including Doctor Elizabeth Lense of the USS Lexington.

Lense later came to appreciate the Mark I EMH's lack of simulated emotionalism.

Starfleet thought the Mark I's personality was too abrasive.

Given these reactions, the Mark I was quickly replaced on many ships by newer versions.

The existing Mark I EMHs were reprogrammed for more menial tasks, such as scrubbing plasma conduits and mining dilithium ore.

Several Mark I EMHs continued to serve in their intended roles, including "The Doctor" of the USS Voyager and the EMH on the USS Equinox: both vessels being stranded in the Delta Quadrant, did not, of course, have access to upgraded versions.

A Mark I EMH also remained on the USS Enterprise-E into 2378, as Chief medical officer Doctor Beverly Crusher preferred it to later versions. Although Doctor Crusher had previously mentioned that she had sworn to never use the EMH.

The USS Destiny also had a Mark I EMH.

The Soong Foundation discovered that more than 600 EMH Mark I models were put into servitude by Starfleet mining dilithium. Soong Foundation attorney Alyssa Cogley-Shaw sued for an injunction for Starfleet to reveal the status of all of its holographic programs. She claimed this was the slavery of sentient lifeforms, but Starfleet appealed the injunction claiming that the Mark I models are photonic tools.

Later versions[]

A second generation EMH

The EMH Mark II was programmed with new physical characteristics and to be a much more polite and friendly individual, although some felt it was too skittish. New starship classes such as the Prometheus-class were fitted with shipwide holographic projection systems so that EMHs could attend emergencies outside of sickbay.

The EMH Mark III came into general use during the height of the Dominion War, and included stringent security protocols. It also featured an improvement of its personality subroutine over the previous models. However, following the end of the war, these security measures came to be viewed as a hindrance to effective caregiving.

The EMH Mark IV came into use in early 2376, replacing the Mark III.

The EMH Mark VI usage was unknown though it was still in operation on starships by 2409 as seen on the USS Khitomer. This version had pale, blueish skin and a personality similar to that of the Mark I.

The EMH Mark IX was online by 2380. This version looked like a young, female with strawberry-blonde hair, and could replicate herself as necessary. A Mark IX nicknamed "Nina" was active aboard the Enterprise in mid 2380.

Nina was often used following heavy combat, especially during the Borg Invasion of 2381.

Following a refit in early 2386, the USS Titan was equipped with a Mark IX.

The EMH Mark XI was in use by 2381.

Other EMHS[]

La Sirena's EMH

In 2399, a civilian ship, La Sirena, possessed an Emergency Medical Hologram as one of multiple specialist emergency holograms. When Jean-Luc Picard beamed aboard the ship to speak with the ship's captain, Cristóbal Rios, Picard was greeted by the EMH, who brought him to meet a wounded Rios. After the EMH partially treated the wound, Rios deactivated him. (PIC episode: "The End is the Beginning")


Please state the nature of the medical emergency. (Upon activation)



Photonic and holographic personnel
Emergency holographic programs positions Command (ECH)ConnCounselingEngineeringHospitality (EHH)Medical (EMH) (25th century EMH Mk I) • Navigational (ENH)R&D (Energy Weapons OfficerMatter-Antimatter SpecialistQuartermaster) • Security (ESH) (Security Gorn (ESG)) • Tactical (Holo Leeta) • Entertainment (OrionVulcan) • Hamlet programsholographic bridge officers (TOS • DS9 • others) • holographic Exocomps (holographic combat drone) • Long-term Medical (LMH)personal Karemma trader UFP emblem. Seal of the Federation Starfleet.
notable versions and variants Medical Android (EMA)EmmetEmmettHolo Leeta (Dabo LeetaMirror Admiral) • Diagnostic Program ("Dr. Zimmerman")The DoctorPhotonic Engineering Officer CandidatePhotonic Tactical Officer CandidateVic FontaineThe Warden
notable templates organic templates Lewis Zimmerman (EMH • Diagnostic) • Julian Bashir (LMH) • Leeta
synthetic templates ExocompsThe Doctor (25th century EMH Mk I) • Vic Fontaine (Counseling) UFP emblem. Seal of the Federation Starfleet.