Maricopa County Election Facts  |  Voting Equipment & Accuracy

Voting Equipment
Maricopa County is the second largest voting jurisdiction in the United States and represents more than 60 percent of Arizona’s registered voters. In 2019, the Maricopa County Board of Supervisors invested in new vote tabulation equipment to meet the needs of the county's 2.6 million registered voters.  This page explains steps the County has taken to ensure the equipment accurately counts all votes.

  About the Equipment

  • Maricopa County’s tabulation equipment went through extensive testing and received federally accredited Election Assistance Commission certification.
  • The Dominion Democracy Suite 5.5B is both federally and state certified.
  • The U.S. Election Assistance Commission certification is an official recognition that a voting system has been tested and has met an identified set of Federal voting system standards.
  • Find the federal certification here:
  • Maricopa County completed a robust procurement process to find a vote tabulation system.
  • With 2.6 million registered voters, Maricopa County needed a vote tabulation system that could accommodate the high volume of voters as well as Arizona’s complex ballot rotation laws.
  • Maricopa County is the second largest voting jurisdiction in the country and represents more than 60 percent of Arizona’s registered voters. It needed tabulation equipment that could handle that volume. 
  • Maricopa County piloted the tabulation equipment in the Madison School District election in November 2019. The county completed a 100% hand count of the results and used the equipment to tabulate the votes. Both the hand count and tabulated results were a 100% match.

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  Before each Election

  • Prior to each election, Maricopa County performs a statutorily required Logic & Accuracy (L&A) test.
  • An L&A test is intended to confirm that votes are attributed to the correct candidates and ballot measures in the election management system (EMS) and that each candidate and ballot measure receives the accurate number of votes.
  • The Secretary of State is responsible for performing an L&A test on all voting equipment prior to each election. The test is overseen by:

    • At least two election staff members (of different political parties).  
    • It was also open to observation by representatives of the political parties, candidates, the press, and the public.
  • Maricopa County’s Logic & Accuracy test was on Oct. 6. Public notice was published in a county-wide newspaper, on the website, and a media advisory invited the press and the public.
  • All three chairs for the county political parties were notified of the test in September and invited via a calendar invite and multiple conversations with staff .

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  L&A and Equipment Security

  • When the system is certified by the Election Assistance Commission and the Secretary of State, a copy of the software and a hash code (similar to an electronic fingerprint) confirming the software version are submitted to the National Institute of Standards and Technology for verification.   
  • Prior to the L&A, the County makes a complete copy of the election program including the certified hash code.  This copy of the software is forwarded to the Secretary of State’s Office.  
  • Prior to each election, the software and hash code are verified to confirm the software system being used for the election is the same system that underwent certification.    
  • For the 2020 General Election, the Secretary of State randomly selected central count and Election Day tabulation equipment to test for accuracy. The central count tabulators are located at the Maricopa County Elections Department and are used to count early ballots. The Election Day tabulators are used in the voting locations for in-person voting on Election Day.
  • The Secretary of State’s Office voted more than 900 test ballots on the machines it randomly selected. These ballots were inserted into each of the selected tabulators and the results were verified to confirm accuracy. Voted contests include federal and statewide contests.  
  • The Secretary of State’s Office performed the testing, not County staff or personnel.  
  • In addition, the Secretary of State’s Office tested how tabulators handle over-voted contests to confirm equipment is providing proper alerts to voters. An over voted contest is one in which the voter selected more candidates than allowed for a particular contest (such as voting for two people for president, instead of just one).
  • The law requires that an errorless count must be made in the L&A testing before the tabulators and software can be approved for us in the election.
  • Maricopa County’s tabulators and software achieved that errorless standard in the L&A test on October 6, 2020. The Secretary of State certified that the voting equipment met the mandatory requirements in the L&A testing standards.
  • The County performed a separate L&A on 100% of all Election Day and Early Voting tabulators. That test also achieved an errorless standard.

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  About Over Votes

  • The evidence overwhelmingly shows that the system used in Maricopa County is accurate and provided voters with a reliable election. 
  • When comparing over votes in the presidential contest, voters in 2016 were six-times more likely to cast an over vote than compared to the new tabulation equipment in 2020. 
  • On Election Day, fewer than 200 ballots had an over vote on the presidential race. 
  • Other contests on the ballot also had much fewer over and under votes than in the past.  

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  About the Hand Count

  • In Arizona, hand counts are performed to verify the machine counts from a sample of ballots from each County.
  • The Maricopa County Elections Department conducted a hand count of two-percent of the Election Day ballots and 1 percent of early ballots as required by Arizona law, and it yielded a 100-percent match to the results produced by the tabulation equipment.  
  • All early ballots included in the hand count draw are selected by political party observers during tabulation. 
  • On Nov. 4, all three political party chairs (or their designees) did a random draw of the early ballot batches and the voting locations that were included in the hand count audit.
  • Hand count audit boards do not include Election Department staff. They are appointed by all three political party chairs (or their designees).        
  • The audit boards are made up of individuals appointed by the Republican, Democratic and Libertarian party chairs. 
  • Audit boards are randomly assigned and made up of bipartisan members. Each audit board signs a tally sheet confirming the total number of ballots counted and the results of each race matches the tabulated results.  
  • The state has a Vote Count Verification Committee made up of statisticians and elections officials that set the margins for conducting hand counts.
  • The group sets the variance rates, which ensure a statistically significant sample is provided.  
  • Therefore, a 100% manual hand count audit of more than 2 million ballots is unnecessary.
  • There are triggers in Arizona law to require another hand count or even a recount in the case of a close contest.  
  • None of those thresholds have been met during the 2020 Election, and all accuracy tests, before and after, prove Maricopa County held a fair election.
  • In 2020, Maricopa County conducted hand count audits after the March Presidential Preference Election, the August Primary Election, and the November General Election. For all three elections, Maricopa County used the Dominion Tabulation Equipment, similar ballot styles, and Sharpie pens. The political party appointees for all three hand-counts found zero variances between hand count results and the Dominion tabulation equipment .   

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  Post-Election L&A

  • After all ballots are counted, the Elections Department completes a post-election L&A on its equipment.
  • This test ensures no changes were made to any software throughout the election and is the final step to verify the election results. 

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