With the advent of the latest starship Enterprise, Starfleet went back to the drawing board for the Sickbay design. Medical progress over the last 20 years meant that the sickbays of current starships were not keeping up with the cutting edge advances. With the aid of the head of Starfleet Medical, Captain Leonard McCoy, the whole sickbay design was reviewed and updated. The biobed design was upgraded, as was the containment forcefields, isolation units and trauma rooms. The new updated biobed comes in two forms: the standard biobed for everyday incidents and intensive care biobeds for those more serious occasions where the condition of the patient is critical and where more detailed and intensive treatment is required. After the initial redesign of sickbay was field tested onboard the Enterprise, Starfleet decided to use the technology for a medical ship variant. U.S.S. Solace, N.C.C. 10341, is presently being tested in the field.

Sheffield can deal with around 200 casualties without stretching her resources or impinging on other areas of the ship. Sheffield has a specialised team of 20 medical staff, most of which are trained for all situations. Medical equipment in sickbay ranges from the handheld scanner and medical tricorders to the aforementioned biobeds and stasis units. Sickbay is located on deck 7 (Room 07 4077) and is in the most protected area of the ship. Smaller sub-sickbays are located in other areas of the ship. New medical facilities include the Mental Trauma Room (on deck 3) which contains facilities imported from Vulcan, Delta IV and Betazed (amongst others) and is designed to treat mental and psionic injuries, especially in races with psionic abilities. There are four fully trained doctors on the ship at any one time (not including temporarily assigned specialists), and there are the most up-to-date medical laboratories installed (Rooms 07 4078-81) with all the latest exomedical treatment and research resources onboard. In addition to the main medical area and laboratories there are specialised isolation wards and treatment rooms that can be used to simulate all known atmospheric and climatic conditions (except "Demon" class). These rooms allow for the treatment of lifeforms in an isolated and comfortable environment to their own biological needs, without the danger of contamination of the shipboard atmosphere.

Sickbay also makes extensive use of other modifications made to Sheffield. Sickbay can monitor the life functions of any of the crew by the use of the biomonitor in the uniform insignia. This allows the sickbay personnel to monitor any crewmember who they have concerns about, without needing them to constantly report their condition. The sickbay also has the benefit of modifications made to the transporter system. The modifications now allow the more seriously injured crew, and other individuals, to be beamed directly to sickbay instead of going via one of the transporter rooms.