Question: What identical process will take place for gubernatorial elections and United States Congress elections if vacancies arise?

Context paragraphs:
United States gubernatorial elections, 2016: United States gubernatorial elections were held on November 8, 2016 in 12 states and two territories.  The last regular gubernatorial elections for nine of the 12 states took place in 2012.  The last gubernatorial elections for New Hampshire, Oregon, and Vermont took place in 2014, as Oregon held a special election due to the resignation of governor John Kitzhaber, while the governors of New Hampshire and Vermont both serve two-year terms.  The 2016 gubernatorial elections took place concurrently with several other federal, state, and local elections, including the presidential election, Senate, and House elections.

United States gubernatorial elections, 1968: United States gubernatorial elections were held on 5 November 1968, in 21 states and one territory, concurrent with the House, Senate elections and presidential election.  These were the last gubernatorial elections for Arizona, New Mexico, and Wisconsin to take place in a presidential election year, as all would extend their governor's terms from two to four years.

United States gubernatorial elections, 2015: United States gubernatorial elections were held in three states.  The elections were held on November 3, 2015 in Kentucky and Mississippi and November 21, 2015 in the state of Louisiana.  These elections form part of the 2015 United States elections.  The last regular gubernatorial elections for all three states were in 2011.

United States gubernatorial elections, 2018: United States gubernatorial elections will be held on November 6, 2018, in 36 states and three territories.  In addition, special elections may take place if other gubernatorial seats are vacated.  These elections form part of the 2018 United States elections.  The last regular gubernatorial elections for all but three of the states took place in 2014.  Governors in New Hampshire and Vermont serve two year terms, meaning that their most recent gubernatorial elections took place in 2016.  Oregon, meanwhile, held a special election in 2016 to fill the unexpired term of John Kitzhaber following his resignation in February 2015; that election was won by the Democratic incumbent Kate Brown, who will serve the final 2 years of the term.

United States gubernatorial elections, 2017: United States gubernatorial elections will be held on November 7, 2017 in two states: Virginia and New Jersey.  These elections form part of the 2017 United States elections.  The last regular gubernatorial elections for these two states were in 2013.  Both incumbents are term-limited, so both seats are open.

United States elections, 2017: The 2017 United States elections will be held (for the most part) on Tuesday, November 7, 2017.  This off-year election will feature gubernatorial elections in Virginia and New Jersey, as well as state legislative elections in both houses of the New Jersey Legislature and in the lower house of the Virginia legislature.  Numerous citizen initiatives, mayoral races, and a variety of other local elections will also occur.  Special elections to the United States Congress may take place if vacancies arise.

United States gubernatorial elections, 2019: United States gubernatorial elections will be held on November 5, 2019 in three states.  In addition, special elections may take place if other gubernatorial seats are vacated.  These elections form part of the 2019 United States elections.  The last regular gubernatorial elections for all three states were in 2015.

United States gubernatorial elections, 1964: United States gubernatorial elections were held 3 November 1964, concurrently with the presidential election.  Elections were held in 25 states and 1 territory.  This was the last gubernatorial elections for Florida, Massachusetts, Michigan, and Nebraska to take place in a presidential election year.  Florida switched its governor election years to midterm years, while the other three expanded their terms from two to four years, this election also coincided with the Senate and the House elections.

United States gubernatorial elections, 2020: United States gubernatorial elections will be held on November 3, 2020 in 11 states and two territories.  In addition, special elections may take place (depending on state law) if other gubernatorial seats are vacated.  The last regular gubernatorial elections for nine of the eleven states took place in 2016.  The last gubernatorial elections for New Hampshire and Vermont will have taken place in 2018, as the governors of both states serve two-year terms.  All state governors will be eligible for re-election, save for Steve Bullock of Montana, although other governors may choose to retire.  The 2020 gubernatorial elections will take place concurrently with several other federal, state, and local elections, including the presidential election.

United States elections, 2019: The 2019 United States elections will be held (for the most part) on Tuesday, November 5.  The off-year election includes gubernatorial and state legislative elections in a few states; as well as numerous citizen initiatives, mayoral races, and a variety of other local offices on the ballot.  Special elections to the United States Congress may take place if vacancies arise.

Supporting paragraphs: United States elections, 2019 United States gubernatorial elections, 2019
Answer: special elections