The USNS prefix identifies Comfort as a non-commissioned ship owned by the U.S. Navy and operationally crewed by civilians from the Military Sealift Command (MSC).

[citation needed] Like her sister ship USNS Mercy, Comfort was built as a San Clemente-class oil tanker in 1976 by the National Steel and Shipbuilding Company.

[clarification needed] Comfort was tasked to provide a 250-bed medically intensive patient capability for the 35,000 Cuban and Haitian migrants supported by Naval Station Guantanamo Bay, Cuba.

Following the diplomatic agreement reached between the United States and Haiti, Comfort took up a position off Port-au-Prince ready to receive casualties that might result from the transfer of U.S. and allied forces ashore.

The ship's clinic saw 561 guests for cuts, respiratory ailments, fractures, and other minor injuries, and Comfort's team of Navy psychology personnel provided 500 mental health consultations to relief workers.

Comfort remained in the Persian Gulf for 56 days providing expert medical care to wounded U.S. military personnel as well as injured Iraqi civilians and enemy prisoners of war.

Comfort's Medical Treatment Facility had also performed 590 surgical procedures, transfused more than 600 units of blood, developed more than 8,000 radiographic images, and treated nearly 700 patients, including almost 200 Iraqi civilians and enemy prisoners of war.

Comfort deployed on 2 September 2005, after only a two-day preparation, to assist in Gulf Coast recovery efforts after the devastation of Hurricane Katrina.

[citation needed] Comfort's Partnership for the Americas humanitarian mission, which began on 15 June 2007, was a major component of the President's "Advancing the Cause of Social Justice in the Western Hemisphere" initiative.

The embarked medical crew was made up of more than 500 military and non-governmental organization (Project Hope and Operation Smile) doctors, nurses, and healthcare professionals.

Comfort was operated and navigated by a crew of 68 civil service mariners (CIVMARS) from the U.S. Navy's Military Sealift Command (MSC).

In addition to treating patients, bio-medical professionals fixed about a thousand pieces of medical equipment at local health facilities.

[citation needed] On 13 January 2010, Comfort was ordered to assist in the humanitarian relief efforts following the 2010 Haiti earthquake as part of Operation Unified Response.

[15] On 10 March 2010, the ship ended her mission in the Joint Task Force Haiti area as part of Operation Unified Response, and returned to her home port.

The ship deployed for five months providing medical and surgical services to nine locations in the Caribbean and Latin America – Jamaica, Peru, Ecuador, Colombia, El Salvador, Nicaragua, Guatemala, Costa Rica, and Haiti.

These temporary medical clinics included primary care, internal medicine, obstetrics, and pediatric physicians as well as optometry, physical therapy, dental, radiology, laboratory, and pharmacy services.

On 29 September 2017, the ship set sail for Puerto Rico to bring assistance to the island after Hurricane Maria had hit it nine days earlier.

[20] While in San Juan, Comfort hosted a summit with key stakeholders to synchronize efforts for the ship's mission throughout the area.

As the island infrastructure improved the admission rate to the ship declined to 1% of patients presenting, she was ordered home on 17 November.

[22] In October 2018, Comfort departed for an eleven-week operation in Latin America, with a primary mission being to assist countries that received refugees who fled the crisis in Venezuela.

The main goal was to relieve health systems in Colombia, Ecuador, Peru and Honduras, which faced the arrival of thousands of Venezuelan migrants.

[33] On 21 April, Governor Andrew Cuomo told President Donald Trump that the ship was no longer needed in New York.

[35] In 2008, the United Seamen's Service at its annual Admiral of the Ocean Sea Awards (AOTOS) event honored the masters and crews of hospital ships Comfort and Mercy with special Humanitarian Service Recognition Mariner's Plaques for their respective four-month humanitarian deployments to Latin America and the Caribbean in 2007 and Southeast Asia and the Pacific in 2008.