In the United States, 43 of the 50 states have an office of lieutenant governor including two states in which the Senator elected Speaker of the state Senate serves in such a capacity. In most cases, the lieutenant governor is the highest officer of state after the governor, standing in for that officer when he or she is absent from the state or temporarily incapacitated. In the event a governor dies, resigns or is removed from office, the lieutenant governor typically becomes governor. (In some states, however, such as Massachusetts, the lieutenant governor becomes acting governor until the next election.)
In 25 states, the governor and lieutenant governor are elected on the same ticket, ensuring that they come from the same political party. In the remaining 18 states, they are elected separately and, thus, may come from different parties. The lieutenant governor is also frequently the presiding officer of the upper house of the state legislature, similar to the Vice President of the United States. Among the seven states without a separate, full-time office of lieutenant governor, two states have a post of lieutenant governor that is filled by the highest officer of the state Senate. In Tennessee, the full title of the leader of the Senate is "Lieutenant Governor and Speaker of the Senate". In West Virginia, the title of Lieutenant Governor is assigned by statute to the Senate President. With the exception of Arkansas, California, Georgia, Idaho, Tennessee, Texas, Virginia, Washington, and West Virginia, every state has had a female Lieutenant-Governor or equivalent - although Mona Pasquil briefly acted as Lieutenant-Governor of California between Abel Maldonado and John Garamendi.
In Maine and New Hampshire, the presiding officer of the State Senate assumes the governor's office upon a vacancy. In the remaining three states – Arizona, Oregon, and Wyoming – the Secretary of State becomes governor upon the office's vacancy.
The U.S. commonwealth of the Northern Mariana Islands and the U.S. territories of American Samoa, Guam, and the Virgin Islands have the office of lieutenant governor. In the U.S. territory of Puerto Rico, the appointed Secretary of State becomes governor upon the office's vacancy.
The positions are sometimes criticized for lacking duties and power and described by political insiders as "get up, read the paper, see if the governor is dead, if not, go back to sleep". In the 2010 election for the lieutenant governor of Rhode Island, 40% of the vote was won by a perennial candidate who wanted to abolish the office, saying "If you open up the dictionary to ‘sinecure,’ you have a picture of the lieutenant governor of Rhode island". There are some exceptions to this. Alaska, Hawaii, and Utah do not have a Secretary of State but the lieutenant governor does these duties instead. In New Jersey, the governor must appoint the lieutenant to head a cabinet-level department or administrative agency within the state government's executive branch—but not to the post of state attorney general, the current holder, Kim Guadagno, serving as the Secretary of State. The Lieutenant Governor of Texas plays an active role as presiding officer of the State Senate and is often rumored to be more powerful than the state governor. The Lieutenant Governor of Virginia also serves as the President of the Senate.
In November 2005, New Jersey voters approved a constitutional amendment to create the office of Lieutenant Governor, which became effective with the 2009 general election. The state's first lieutenant governor took office in January 2010.
The position was created in response to the unusual circumstances surrounding the aftermath of the 2001 gubernatorial election. At the time Senate President Donald DiFrancesco was acting as governor following the resignation of Christine Todd Whitman earlier that year. DiFrancesco's term as Senate president expired one week before the governor-elect assumed office in January 2002, necessitating a special arrangement in which the party leaders of the incoming Senate switched off as acting governor (each serving a few days) until Jim McGreevey was sworn in. All told, five people had served as governor in the space of one year.
In Arizona, the secretary of state is the first in line to succeed the governor in the event of death, disability, resignation, or removal from office. The line of succession also includes the attorney general, state treasurer and superintendent of public instruction.
In Maine, if the governor suddenly leaves office, the immediate successor is the Senate President.
Whenever the governor is unable to perform the duties of office, the Senate president serves as "acting governor".
The gubernatorial line of succession is set forth in the state constitution, at Article V, Section 8a. It defines who may become or act as the Governor of Oregon upon the incapacity, death, resignation, or removal from office (by impeachment and subsequent removal or recall) of a sitting governor. The acting governor or new governor serves the remainder of the incapacitated or previous governor's term. In 2007, legislation was proposed to establish an office of Lieutenant Governor. The current chain is: Secretary of State, State Treasurer, President of the State Senate, Speaker of the House of Representatives.
In Tennessee, the senators elect a Speaker of the Senate, who in turn serves as Lieutenant Governor of Tennessee.
West Virginia's lieutenant governor serves only in an honorary capacity; the title is conferred upon the president of the West Virginia Senate, who is constitutionally first in the line of succession as governor.
In Wyoming, the secretary of state stands first in the line of succession.
When the Governor is temporarily disabled or unable to discharge his/her duties, sections 7 and 8 of the Constitution empower the Secretary of the Puerto Rico State Department to act as Governor. If there is a permanent vacancy in the governorship, he becomes governor for the remainder of the term. He serves as Acting Governor whenever the elected Governor is temporarily not present in Puerto Rico.