Liquefied natural gas (LNG) is natural gas (predominantly methane, CH4) that has been converted to liquid form for ease of storage or transport. Liquefied natural gas takes up about 1/600th the volume of natural gas in the gaseous state. It is odorless, colorless, non-toxic and non-corrosive. Hazards include flammability after vaporization into a gaseous state, freezing and asphyxia. LNG is produced by taking natural gas from a production field, removing impurities, and liquefying the natural gas.  In the liquefaction process, the gas is cooled to a temperature of approximately-260 degrees F at ambient pressure.

This condensed liquid form of natural gas takes up about 1/600th of the volume of natural gas at a stove burner tip. The LNG is loaded onto double-hulled ships which are used for both safety and insulating purposes. Once the ship arrives at the receiving port, the LNG is typically off-loaded into well-insulated storage tanks. Regasification is used to convert the LNG back into its gas form, which enters the domestic pipeline distribution system and is ultimately delivered to the end-user.

Natural gas consumption in the United States is expected to increase slightly from about 24.3 trillion cubic feet (Tcf) in 2011 to 26.6 Tcf by 2035. Currently, most of the demand for natural gas in the United States is met with domestic production and imports via pipeline from Canada. A small percentage of gas supplies are imported and received as liquefied natural gas. A significant portion of the world's natural gas resources are considered "stranded" because they are located far from any market.  Transportation of LNG by ship is one method to bring this stranded gas to the consumer.

In 2011, the United States imported 349 billion cubic feet (Bcf) of LNG from seven different exporting countries, with the largest being Trinidad and Tobago.  Imports in 2011 decreased by 19 percent from 431 Bcf in 2010. There are currently twelve LNG import terminals located along the Atlantic and Gulf coasts. The mainland terminals are:  Everett, Massachusetts; Cove Point, Maryland; Elba Island, Georgia; Lake Charles, Louisiana; Sabine Pass, Louisiana; Cameron, Louisiana; Golden Pass, Texas; Freeport, Texas; and Gulf LNG, Mississippi.

These nine facilities have a total baseload sendout capacity of approximately 16.1 Bcf/day. The offshore terminals are Gulf Gateway Energy Bridge in the Gulf of Mexico and Northeast Gateway and Neptune Deepwater Port located offshore Massachusetts, with a baseload sendout capacity of 1.2 Bcf/day, though Excelerate Energy has announced plans to retire the Gulf Gateway terminal. As of December 2012, FERC reported 13 new or expanded North American LNG import terminal projects that have been approved or proposed, one of which is under construction. FERC also identified 10 North American LNG export terminal projects that have been proposed, one of which is under construction. Some projects include both import and export capabilities.