Colorado's election system wasn't built overnight. It developed over decades as voters changed how they registered, how they voted and how they expected elections to work.
Today's model is the latest chapter in a much longer Colorado story.
HB92-1004 establishes no-excuse absentee voting and expands voting before Election Day. The same year, Colorado voters approve TABOR.
02
1992 | TABOR + mail ballots
TABOR puts specified tax and fiscal questions before voters, while Colorado's mail-ballot framework allows those elections to be conducted by mail.
03
2003–07 | The model keeps evolving
Vote centers emerge in Larimer County, followed by the Permanent Mail-In Voter framework that lets voters choose to keep receiving ballots by mail.
04
2009 | Mail primaries + auditing
Colorado authorizes mail-ballot primaries and enacts the statutory requirement for risk-limiting audits.
05
2013 | Voter behavior leads the way
70.9% of voters statewide were already on the PMIV list when HB13-1303 passed.
06
Continuous improvement
State and federal changes continue shaping the model: uniform voting systems, RLAs, AVR, military and overseas voting protections, cybersecurity, insider-threat protections, sustainable funding and stronger audits.
Still evolving →
A pivotal connection
1992: TABOR changes the election landscape
Colorado voters approved the Taxpayer's Bill of Rights, commonly known as TABOR. Among other provisions, TABOR requires voter approval for specified tax increases and other fiscal questions.
Colorado law allowed TABOR ballot-issue elections to be conducted as mail-ballot elections.
That matters. Long before statewide mail-ballot delivery, voters in communities across Colorado could receive ballots at home to decide tax, debt and other fiscal questions. Voting by mail became a familiar part of civic life.
2013 wasn't Colorado's introduction to mail ballots. It was another major step in a system that had been evolving for decades.
What is TABOR? +
TABOR was approved by Colorado voters in 1992. It requires voter approval for specified tax increases and other fiscal matters. Colorado election law provides for TABOR ballot-issue elections as coordinated elections or independent mail-ballot elections.
From precincts to today's hybrid model
How Colorado's voting model evolved
In 1990, Colorado elections centered on precinct polling places, excuse-required absentee ballots, no early voting and firm registration deadlines. Over the next two decades, the state steadily added choices that voters increasingly used.
1990
The traditional model begins to change
Colorado elections still center on precinct polling places, excuse-required absentee voting, no early voting and firm registration deadlines. That year, Colorado also enacts the Mail Ballot Election Act, creating a statutory framework for certain elections to be conducted by mail.
1992
Colorado expands voting beyond Election Day
HB92-1004 establishes no-excuse absentee voting, allowing Colorado voters to request an absentee ballot without providing a qualifying reason. The legislation also expands Colorado's early-voting framework.
The same year, Colorado voters approve TABOR. Specified tax and fiscal questions must go to voters, and Colorado's mail-ballot framework allows those elections to be conducted by mail. Together, these changes help make voting away from a traditional Election Day polling place increasingly familiar.
1993
Early voting develops further
Colorado follows the 1992 changes with additional legislation refining the state's early-voting framework.
1993
Federal NVRA expands voter registration
Congress enacts the National Voter Registration Act, often called “Motor Voter.” The federal law expands registration opportunities through motor vehicle agencies, mail applications and designated public agencies, while also establishing requirements for voter-list maintenance.
2002
HAVA modernizes election administration
Following the 2000 presidential election, federal law brings new voting-system standards, accessibility requirements, provisional ballots, statewide registration-system requirements and the Election Assistance Commission.
2003–04
Vote centers emerge
Larimer County pilots vote centers in 2003. Colorado establishes statewide statutory authority for the model in 2004.
2007
Permanent Mail-In Voting
SB07-234 establishes the Permanent Mail-In Voter framework. Eligible voters can choose permanent mail-in status so they continue receiving mail ballots without making a new request election after election.
2009
Mail-ballot primaries + risk-limiting audits
Colorado authorizes primary elections to be conducted by mail and enacts the statutory requirement for risk-limiting audits, later implemented statewide in 2017.
2009–10
Federal MOVE Act strengthens voting for military and overseas citizens
Congress expands UOCAVA through the Military and Overseas Voter Empowerment Act. Among its major changes, states must provide electronic options for receiving registration and ballot materials and transmit validly requested absentee ballots to covered voters at least 45 days before federal elections when the request is received by that deadline. Most requirements take effect for the 2010 election cycle.
2010
Online voter registration
Colorado launches online voter registration, adding another way for eligible voters to maintain their registration.
2012
Colorado helps launch ERIC
Colorado is one of seven founding states of the Electronic Registration Information Center, designed to improve voter-list accuracy using registration and motor-vehicle data.
2013 | HB13-1303
A milestone, not a starting line
70.9%
of Colorado voters were already on the Permanent Mail-In Voter list when HB13-1303 passed.
2013 brought existing pieces together.
The Voter Access and Modernized Elections Act made mail-ballot delivery standard for active registered voters while preserving strong in-person voting through Voter Service and Polling Centers. It also added same-day registration.
What did HB13-1303 change? +
Mail-ballot delivery: Active registered voters receive a ballot by mail.
In-person voting: Voter Service and Polling Centers preserve a robust in-person option for voters who want or need it.
Same-day registration: Eligible Coloradans can register and vote in person through Election Day.
A statewide model: The law brought together practices Colorado had been developing for years, including mail voting and vote centers, into the foundation of today's hybrid election model.
2015–17
Uniform voting systems + security modernization
Colorado moves toward a more uniform statewide voting-system environment as election cybersecurity becomes a major national focus.
2016–18
Unaffiliated voters enter party primaries
Voters approve Propositions 107 and 108 in 2016. Implementation legislation follows in 2017, and unaffiliated voters begin participating in major-party primaries under the new model in 2018.
2017
First statewide risk-limiting audit
Colorado becomes the first state to complete a statewide risk-limiting audit, using paper ballots to statistically test reported outcomes.
2017–20
Automatic voter registration develops
Colorado's DMV/SCORE registration process evolves through implementation work and additional 2019 legislation.
What changed with AVR? +
The work began before implementation. Colorado election officials and state partners had been examining Motor Voter and registration modernization for several years before the 2017 changes.
2017: Colorado moves forward with automatic voter-registration changes tied to the state's voter-registration and motor-vehicle systems.
2019–20: Additional legislation expands and clarifies the electronic-transfer process.
The broader trend predates AVR: Colorado already had a substantial unaffiliated electorate before automatic voter registration. AVR arrived amid longer-running changes in party registration rather than marking the beginning of those changes.
See the registration trend +
Active registered voters by affiliation
● Unaffiliated● Democratic● Republican● Minor
The graph shows chronology, not causation. The 2017 marker provides context for when AVR entered the timeline.
2018
National attention for Colorado's security model
The Washington Post publishes “How Colorado became the safest state to cast a vote,” highlighting paper ballots, audits and election-security practices.
Colorado strengthens protections against insider threats
Election security is not only about threats from outside an election office. Colorado strengthened state law and election rules to reduce the risk that someone with authorized access could misuse that access.
New safeguards tightened physical and electronic access to voting systems, background-check requirements, trusted-build procedures, video surveillance, security seals and administrative privileges.
What changed? +
ACCESS
Stronger controls over who can access voting equipment and secure areas.
ACCOUNTABILITY
Background checks, documented privileges and tighter administrative access, along with stronger election offenses and penalties for unauthorized access, disclosure of protected voting-system information, and other violations of election law.
PHYSICAL SECURITY
Video surveillance, seals and custody requirements.
RISK MANAGEMENT
Resources and ongoing assessments to help counties strengthen election security.
The principle: No individual should have unchecked access to critical election systems.
2023
Colorado modernizes how elections are funded
As Colorado's election system became more sophisticated, the cost of administering it changed too. SB23-276 replaced the longstanding per-active-voter reimbursement approach with a model tied more closely to actual election costs.
45%
The state's share of necessary and reasonable county election costs for elections with state-certified ballot content under the new reimbursement model.
Modern elections require sustainable funding for staffing, equipment, facilities, ballot processing, security and other election operations.
An important distinction
Colorado is a mail-ballot delivery state, not simply an “all-mail” state.
Every active registered voter receives a ballot by mail, but every voter also has access to in-person voting through Voter Service and Polling Centers.
MAIL-BALLOT DELIVERY
Active registered voters receive ballots automatically and can return them by mail or at a ballot drop box.
IN-PERSON VOTING
Voters can instead visit a VSPC to register or update their registration, obtain a replacement ballot, receive assistance or vote in person.
Colorado's modern model is hybrid by design: broad mail-ballot delivery plus robust in-person voting.
The Colorado model today
Access evolved. So did security.
DELIVERActive registered voters receive a ballot.
CHOOSEVote that ballot or vote in person.
VERIFYMail-ballot signatures are verified.
PROTECTBallots, systems and facilities are secured.
RECONCILEOfficials account for ballots and participation.
AUDITPaper ballots independently test reported outcomes.
And the infrastructure around those steps continues to evolve: Colorado has added stronger insider-threat protections and modernized how the state shares the cost of administering elections with counties.
1876 Military absentee voting · 1893 Women's suffrage · 1910 Initiative and referendum · 1947 Excuse-required absentee voting · 1965 Voting Rights Act · 1971 Voting age becomes 18 · 1980 Homeless-voter provisions · 1984 Colorado Motor Voter.
1990–2006 | New ways to vote +
1990 Mail Ballot Election Act · 1992 TABOR and no-excuse absentee voting · 1993 Signature verification · 1996 Early voting · 2002 Provisional ballots and HAVA · 2005 Vote centers and random audits · 2006 Electronic transmission of military ballots.
Colorado's election model does not improve on its own. County clerks administer elections year after year, giving them a direct view of what works, what needs attention and where additional transparency or safeguards can make the system stronger.
This work has been practitioner-driven and multipartisan. Colorado election officials include Republicans, Democrats and unaffiliated clerks working under the same election laws and confronting the same operational challenges. The improvement agenda described here grew from the experience of Colorado election professionals administering the system, identifying gaps and proposing ways to strengthen election integrity, accuracy and transparency.
Signature verification
Audit the process, not just the vote count.
In 2021, CCCA proposed a formal statewide audit of signature verification, similar in concept to Colorado's risk-limiting audit, to test whether signature review is being conducted consistently and correctly across the state.
Election funding
Modernize how elections are funded.
CCCA called for replacing an outdated reimbursement approach that no longer reflected the actual cost of administering increasingly complex and secure elections. Colorado later adopted a new reimbursement model tied more closely to necessary and reasonable county election costs.
Transparency + trust
Make the evidence easier to see.
Colorado clerks have supported greater access to election evidence, including ballot images, cast vote records and additional audit concepts. Clerks have also worked to correct false or misleading claims about election administration. These are related efforts, but the integrity improvements themselves were developed by election professionals as part of the continuing work to test, validate and strengthen Colorado's processes.
Risk-limiting audits
Keep improving an industry-leading audit.
Colorado pioneered statewide risk-limiting audits. County clerks continue working to make the RLA more transparent, understandable and useful while preserving its core purpose: independently testing reported election outcomes.
Continuous improvement is part of the Colorado model. Republican, Democratic and unaffiliated election officials help identify gaps, test improvements and strengthen the integrity, transparency and security of election administration.
CCCA's continuous-improvement agenda +
CCCA's 2021 recommendations were informed by Colorado election officials with different political affiliations and by their direct experience administering elections. The recommendations called for public access to ballot images and cast vote records, stronger signature-verification auditing, review of voter-list maintenance, and modernized election funding.
The purpose was continuous improvement in election integrity. These were election professionals asking how an already mature system could be tested more rigorously, made more consistent and opened to greater independent verification. The work should not be understood simply as a reaction to election denial or misinformation.
That same practitioner-led approach continues today. Colorado clerks are working to strengthen the consistency and transparency of signature-verification auditing and are helping lead work to improve the state's risk-limiting audit framework so it remains rigorous while becoming clearer, more transparent and more useful.
The story continues
The Colorado model is still evolving.
Colorado's election system has never been static. Over more than three decades, the state has changed how voters receive ballots, where they can vote, how they register, how ballots are verified, how results are audited, how systems are protected and how elections are funded.
Many of those changes followed something equally important: how Colorado voters were already choosing to participate.
Keep exploring
Three pages. One Colorado election story.
How We Got Here
Why Colorado's system developed this way.
YOU ARE HERE
How Colorado Secures Your Vote
See the safeguards that protect ballots, systems and results.
Source notes for production: Historical framing is based on CCCA's 2019 New Clerks Training, supplemented by legislative verification. Key sources include HB92-1004 for no-excuse absentee voting and voting before Election Day, and HB93-1255 for subsequent early-voting refinements; HB13-1303 for the modern mail-ballot/VSPC model; Colorado legislative materials for later changes; and the Washington Post's 2018 profile of Colorado election security. The PMIV milestone uses 2007, consistent with the Colorado Secretary of State chronology supplied for this project and SB07-234. The 70.9% PMIV figure should be linked to its original statewide source before publication.
