This explainer was last updated on August 21, 2026.
Legal basis
For decades, Congress has sought to reduce the voting barriers experienced by military and overseas voters through legislation, including the Soldier Voting Act of 1942, the Federal Voting Assistance Act of 1955, and the Overseas Citizens Voting Rights Act of 1975. These laws, however, were limited in scope and lacked a uniform system for implementation. In 1986, Congress passed the Uniformed and Overseas Citizens Voting Act (UOCAVA), providing a legal mechanism for eligible members of the military, their family members, and civilians living abroad to vote absentee in federal elections. UOCAVA also created the Federal Voting Assistance Program (FVAP) within the Department of Defense (DoD) and entrusted the program with administering the Act. To this day, UOCAVA governs the voting process for military and overseas citizens in all elections for federal office.
Nearly twenty years after UOCAVA’s passage, Congress provided further support to military and overseas citizens by enacting the Military and Overseas Voter Empowerment (MOVE) Act in 2009. The MOVE Act required states to establish procedures for UOCAVA voters to request and receive voter registration and absentee ballot applications electronically. It also required the Department of Defense to establish voting assistance offices on military installations and mandated that states send ballots to UOCAVA voters at least 45 days prior to federal elections.
In addition to UOCAVA and the MOVE Act, parts of the National Voter Registration Act (NVRA) of 1993 and the Help America Vote (HAVA) Act of 2002 also apply to military and overseas voters. Under the NVRA, the DoD was required to implement voter registration procedures at military recruitment offices, similar to those used by ordinary citizens at state motor vehicle bureaus. HAVA also required the DoD to inform voters about registration procedures and absentee ballot deadlines—responsibilities mirroring those required of states for non-UOCAVA voters. HAVA also laid the groundwork for a more uniform application of UOCAVA requirements across states, a goal more fully realized by the MOVE Act.
Who are UOCAVA voters?
UOCAVA voters include U.S. citizens who are active duty members of the military, members of the Merchant Marine, the commissioned corps of the Public Health Service and the National Oceanic and Atmospheric Administration, their family members, and U.S. civilians residing abroad. More broadly, the UOCAVA population can be segmented into its two largest subpopulations—the active duty military and civilians living abroad. Active duty members of the military and their family members do not have to be deployed overseas to qualify as a UOCAVA voter. The law’s provisions also apply to those who are stationed within the U.S., but outside the district in which they are registered to vote.
Despite UOCAVA’s defined scope, it is difficult to estimate the size of the eligible UOCAVA voting population given the limited mechanisms available to identify the number of citizens living abroad. Moreover, if UOCAVA voters register and vote using traditional absentee methods, they are counted among the general population and not captured by any administrative assessments aimed specifically at measuring the UOCAVA population. FVAP seeks to conduct the most accurate analysis of overseas voters through the biannual Overseas Citizen Population Analysis (OCPA), which estimated that in 2024, there were approximately 3.3 million citizens living overseas, of whom 2.2 million were old enough to vote. This is more than twice the number of active duty members of the military that are eligible to vote, which stood at approximately 923,000 in 2024.
Registration and voting
UOCAVA voters must be registered to vote in a given state or territory like any other U.S. voter. There are, however, additional methods of registration available to UOCAVA voters compared to citizens. Unlike traditional voters, military and overseas citizens can use the Federal Post Card Application (FPCA) to register to vote, request an absentee ballot, and update their contact information with their local election office. Depending on the state, UOCAVA voters can also use the Federal Write-in Absentee Ballot (FWAB) to register to vote.
Like any other voter, military service members may appear in-person at their polling place on Election Day to cast their ballot, but this is rare. Most military and overseas citizens instead vote using an absentee ballot pursuant to the laws of the state in which they are registered. Alternatively, UOCAVA voters may also use the FWAB as a back-up ballot if they do not receive their absentee ballot in time to meet their state’s deadline. If a voter uses the FWAB, they may be limited to voting in races for federal office given varying state restrictions on using the FWAB to vote in state and local races.
Absentee voting procedures, such as ballot transmission and return methods and deadlines, often differ for UOCAVA voters compared to regular absentee voters. To help UOCAVA voters navigate these procedures, FVAP provides an online tool featuring state- and territory-specific voting information for both military and overseas voters. FVAP also consolidates this information into the Voting Assistance Guide, which is available both digitally and in print.
Trends in UOCAVA Voting
Data from the Election Administration and Voting Survey (EAVS), administered by the U.S. Election Assistance Commission (EAC), can help identify trends in UOCAVA voting across federal election cycles. Although not all states report their data to the EAC, it is possible to discern several important trends in recent years. As demonstrated by the jagged lines in Figure 1 below, there have been significant changes in turnout across presidential and midterm elections since 2008, with fewer ballots transmitted, returned, and counted for UOCAVA voters in midterm elections (similar to domestic trends). Perhaps the most important detail shown in this figure is the fraction of ballots counted as the ratio of ballots returned. This ratio is consistently very high and has increased marginally between each of the last five presidential elections. However, there is still progress to be made in terms of reducing the gap between ballots transmitted and ballots returned.
The figure above depicts a line graph showing the total number of UOCAVA ballots transmitted, returned, and counted in all federal elections since 2008. The green line represents the total number of UOCAVA ballots transmitted, while the gold line represents the total number of UOCAVA ballots returned. The purple line represents the total number of UOCAVA ballots counted.
Note: 2024 UOCAVA ballot totals in Figure 1 exclude data from all 67 counties in Alabama, one county in Arkansas, two counties in Ohio, and Puerto Rico due to missing EAVS data for ballots returned, skewing the ratio of ballots returned to ballots counted. These jurisdictions did report data for ballots transmitted. If transmitted ballots for these jurisdictions were included in the graph, it would show that states reported sending more ballots to UOCAVA voters in 2024 than in previous elections.
The figure above depicts a line graph showing the total number of UOCAVA ballots transmitted, returned, and counted in all federal elections since 2008. The green line represents the total number of UOCAVA ballots transmitted, while the gold line represents the total number of UOCAVA ballots returned. The purple line represents the total number of UOCAVA ballots counted.
Note: 2024 UOCAVA ballot totals in Figure 1 exclude data from all 67 counties in Alabama, one county in Arkansas, two counties in Ohio, and Puerto Rico due to missing EAVS data for ballots returned, skewing the ratio of ballots returned to ballots counted. These jurisdictions did report data for ballots transmitted. If transmitted ballots for these jurisdictions were included in the graph, it would show that states reported sending more ballots to UOCAVA voters in 2024 than in previous elections.
Given that states report data to the EAVS for all UOCAVA voters and broken out by voter type—uniformed service members and overseas citizens—examining the voting patterns of each group reveals several key trends. Since 2014, overseas citizens have constituted the majority of the UOCAVA population, with states having transmitted approximately 793,817 ballots to overseas citizens in 2024 compared to 345,654 ballots transmitted to military voters (see Figure 2 below). Data also show that the number of citizens participating in U.S. elections while living abroad has grown significantly since 2008 and outpaced that of military service members. In 2008, states transmitted approximately 313,137 ballots to overseas citizens, growing to 793,817 in 2024. This constitutes an increase of approximately 154% in the number of ballots transmitted to overseas citizens during this time period. In contrast, the overall number of ballots sent to uniformed service voters decreased from 456,280 in 2008 to 345,654 in 2024, constituting a decline of approximately 24%.
The figure above depicts a line graph showing the total number of ballots transmitted to overseas citizens and uniformed service members in every federal election since 2008. The solid line represents ballots transmitted to uniformed service voters and the dashed line represents ballots transmitted to overseas citizens.
The figure above depicts a line graph showing the total number of ballots transmitted to overseas citizens and uniformed service members in every federal election since 2008. The solid line represents ballots transmitted to uniformed service voters and the dashed line represents ballots transmitted to overseas citizens.
Despite differences in the volume of ballots transmitted to UOCAVA voters, ballots return rates have remained relatively stable. In both 2008 and 2024, approximately 66% of ballots transmitted to overseas citizens were returned compared to 72% of those transmitted to uniformed service members (see Figure 3 below). Differences in ballot return rates between these two groups are indicative of the enduring and unique voting challenges faced by military service members. For example, these voters are frequently assigned new duty stations, which can make receiving election materials and mailed ballots difficult. Similar challenges arise for military service members who are stationed on navy ships, where they may face difficulties with both receiving and returning their ballots given limited access to mail and the internet. Despite these challenges, data show that in 2024, once local election officials received a military or overseas ballot, they were counted at similar rates—96% and 97% respectively (see Figure 4 below).
Figure 3 above (left) depicts a line graph showing the total number of ballots returned by overseas citizens and uniformed service members in every federal election since 2008. Figure 4 above (right) depicts a line graph showing the total number of ballots counted that were returned by overseas citizens and uniformed service members in every federal election since 2008. In both graphs, the solid line represents these figures for uniformed service voters and the dashed line represents these figures for overseas citizens.
Note: As with Figure 1, 2024 UOCAVA ballot totals in Figure 3 and Figure 4 exclude data from all 67 counties in Alabama, one county in Arkansas, two counties in Ohio, and Puerto Rico due to missing EAVS data for ballots returned, skewing the ratio of ballots returned to ballots counted.
Figure 3 above (left) depicts a line graph showing the total number of ballots returned by overseas citizens and uniformed service members in every federal election since 2008. Figure 4 above (right) depicts a line graph showing the total number of ballots counted that were returned by overseas citizens and uniformed service members in every federal election since 2008. In both graphs, the solid line represents these figures for uniformed service voters and the dashed line represents these figures for overseas citizens.
Note: As with Figure 1, 2024 UOCAVA ballot totals in Figure 3 and Figure 4 exclude data from all 67 counties in Alabama, one county in Arkansas, two counties in Ohio, and Puerto Rico due to missing EAVS data for ballots returned, skewing the ratio of ballots returned to ballots counted.
Figure 3 above (left) depicts a line graph showing the total number of ballots returned by overseas citizens and uniformed service members in every federal election since 2008. Figure 4 above (right) depicts a line graph showing the total number of ballots counted that were returned by overseas citizens and uniformed service members in every federal election since 2008. In both graphs, the solid line represents these figures for uniformed service voters and the dashed line represents these figures for overseas citizens.
Note: As with Figure 1, 2024 UOCAVA ballot totals in Figure 3 and Figure 4 exclude data from all 67 counties in Alabama, one county in Arkansas, two counties in Ohio, and Puerto Rico due to missing EAVS data for ballots returned, skewing the ratio of ballots returned to ballots counted.
Examining registration and participation rates of both uniformed service members and overseas citizens can provide additional insight into their voting experiences. Following each general election, FVAP administers the Post-Election Voting Survey – Active Duty Military (PEVS-ADM) to identify voting trends among active duty military voters. As illustrated in Figure 5, the most recent PEVS-ADM found that registration among ADM was 67% in 2024 compared to 69% in 2020. Overall, registration among ADM has plateaued in recent years and remains lower than in the 2008 and 2012 general elections.
The figure above shows a line graph with four separate lines representing the registration rate of active duty military, the citizen voting age population, the citizen voting age population ages 18-24, and the citizen voting age population ages 25-44 in general election years 2008 - 2024.
The figure above shows a line graph with four separate lines representing the registration rate of active duty military, the citizen voting age population, the citizen voting age population ages 18-24, and the citizen voting age population ages 25-44 in general election years 2008 - 2024.
Registration among ADM has also been consistently lower than the general Citizen Voting Age Population (CVAP) since 2016. However, when analyzed by age group, interesting trends emerge (see Figure 5). According to Military OneSource and the Defense Manpower Data Center, 92% of all ADM are between the ages of 18 and 40. When comparing ADM and CVAP registration rates by age group, we see that registration among ADM has been on par with that of citizens aged 25-44 in recent years, but measurably higher than that of all citizens aged 18-24. Given that FVAP registration figures are not disaggregated by age, there are significant opportunities for further research to better understand ADM registration rates by age group and how these rates compare to civilian voters of similar age.
Through the PEVS-ADM and the OCPA, researchers and policymakers also have access to reliable data regarding voter participation for both military and overseas voters. When supplemented with data from the U.S. Census Bureau Current Population Survey Voting and Registration Supplement, the results of these surveys highlight differences in voting rates between military service members, overseas citizens, and the CVAP. As Figure 6 shows, voter participation among ADM has remained relatively stagnant throughout the past three presidential elections, averaging approximately 46%. Participation among overseas citizens increased slightly (by approximately .5 percentage points) in 2024 compared to the 2020 general election, but remains significantly below that of ADM and the CVAP.
The figure above shows a line graph with three separate lines for voter participation rates among active duty military, the citizen voting age population, and overseas citizens in general election years 2014 - 2024.
The figure above shows a line graph with three separate lines for voter participation rates among active duty military, the citizen voting age population, and overseas citizens in general election years 2014 - 2024.
Low voter participation rates among overseas citizens are a long-standing trend that has shown little improvement. However, longitudinal studies of voting behavior among this group are limited given the various challenges associated with identifying and surveying U.S. citizens living abroad, particularly eligible U.S. citizens of voting age. Estimates produced by host-country statistical agencies for the number of U.S.-born or U.S.-citizen populations vary significantly by country and year, and comprehensive estimates for a given election year are often not available. Since 2014, FVAP has utilized a statistical model-averaging methodology to address these constraints, but challenges still remain. Moreover, it is unclear to what extent the traditional problems associated with self-reported voting also apply to military and overseas voters, but there is little evidence that they are not equally applicable.
Politically, UOCAVA citizens are as varied in their attitudes and preferences as any other segment of the broader voting population. Some research suggests that enlisted members of the military are less likely to be strong partisans than their civilian counterparts, while officers tend to lean more Republican than Democrat. It should be noted, however, that political studies of the military population are rare and the results limited given that this group is difficult to sample and mostly shielded from traditional survey efforts.
State and national-level trends impacting UOCAVA voters
Recent changes to fax services offered by FVAP may impact voter participation and voting success among military and overseas voters. During Operation Desert Storm in the 1990s, FVAP initiated the Electronic Transmission Service (ETS) to help UOCAVA voters overcome potential barriers imposed by lengthy mail delivery to and from the Middle East. Through the ETS, UOCAVA voters could email FVAP with attached election materials or ballots to be forwarded to localities by fax. In August 2025, FVAP ended this service for all voters. Although very few UOCAVA voters report using fax to return their ballot, for voters in six states, it is the only available alternative to mail. These states include Alaska, California, Florida, Louisiana, Oklahoma, and Texas. UOCAVA voters and election officials alike will likely experience the impacts of this change throughout the next federal election cycle as voters resort to returning their ballot via mail or faxing their ballot to their local election office.
More recently, federal legislation has proposed sweeping reforms to the conduct of American elections, including the way military and overseas citizens can register to vote. The Safeguard American Voter Eligibility (SAVE) Act (H.R. 22) was introduced in Congress in 2025 and would have required individuals to provide documentary proof of citizenship when registering to vote. This requirement could have restricted mail and online registration and potentially required UOCAVA voters to submit documentary proof of citizenship in person at their local election office. The SAVE America Act (H.R. 7296, S. 3752, S. 1383), introduced in 2026, proposed similar proof-of-citizenship requirements for all voters in federal elections. Although neither bill has been enacted, and Senate efforts to advance the SAVE America Act failed in June 2026, both measures reflect ongoing national debates over voter eligibility verification that could impact UOCAVA voters’ ability to participate in American elections.
While recent federal legislation has targeted voter registration requirements, litigation out of Mississippi challenged mail voting grace periods for absentee voters, including military and overseas citizens. In June 2025, Watson v. Republican National Committee (RNC) was filed with the U.S. District Court for the Southern District of Mississippi. The case centered on whether a federal election statute establishing a uniform, national Election Day for federal elections preempted Mississippi state law allowing for ballots received up to five days after an election to be counted. At the time of the case’s consideration, Mississippi was one of fourteen states that allowed by-mail and absentee ballots postmarked by Election Day to be counted if received within a set period of time following the election. In 2024, an additional eleven states that required domestic absentee and by-mail ballots to be received by Election Day provided extra time for UOCAVA ballots to be received. In June 2026, the Supreme Court upheld the state’s mail voting grace period, but the case’s consideration signals growing efforts to restrict policies that have expanded ballot access for UOCAVA voters.
Suggested readings
U.S. Election Assistance Commission. 2024. “The Election Administration and Voting Survey: 2024 Comprehensive Report.”
Federal Voting Assistance Program. 2023. “Overseas Citizen Population Analysis.”
Federal Voting Assistance Program. 2023. “Post-Election Voting Survey - Active Duty Military.”
Hall, Thad E. 2008. “UOCAVA: A State of the Research.” Caltech/MIT Voting Technology Project VTP Working Paper (69).
Hall, Thad E. 2014. “Voting from Abroad: Evaluating UOCAVA Voting.” In The Measure of American Elections, ed. Barry C. Burden, and Charles Stewart III. New York: Cambridge University Press pp. 141–165.
Inbody, Donald S. 2015. “Voting by Overseas Citizens and Military Personnel.” Election Law Journal 14 (1): 54–59.
Inbody, Donald S. 2016. The Soldier Vote: War, Politics, and the Ballot in America. New York: Palgrave Macmillan.
Smith, Claire M. 2014. Convenience Voting and Technology: The Case of Military and Overseas Voters. New York: Palgrave Macmillan.