State Summary

In 2009, the Colorado General Assembly determined that “risk-limiting audits provide a more effective manner of conducting audits than traditional audit methods in that risk-limiting audit methods typically require only limited resources for election races with wide margins of victory while investing greater resources in close races.” Colo. Rev. Stat. §1-7-515(1)(a). The statute thus required, starting with the 2017 coordinated election and following each primary, general, coordinated, or congressional vacancy election held thereafter that each county conduct a risk-limiting audit. Colo. Rev. Stat. §1-7-515(2)(a). Races to be audited are selected in accordance with procedures established by the secretary of state, and all contested races are eligible for such selection. See Colo. Rev. Stat. §1-7-515(2)(a). The audit must be completed before the official election outcomes are finalized. See Colo. Rev. Stat. §1-7-515(5)(b); see also 8 Colo. Code Regs. § 1505-1:25.2.2(j)(6). The RLA will continue until the risk limit for the target contests is met or until a full hand count results. 8 Colo. Code Regs. § 1505-1:25.2.3(c).

In 2023, a new rule was added to allow counties conducting instant runoff voting elections (ranked choice voting) to develop their own audit of an instant runoff election as long as the audit does not interfere with Colo. Rev. Stat. §1-7-515. See 8 Colo. Code Regs. § 1505-1:26.9.

Unless otherwise specified, references are to 8 Colo. Code Regs. § 1505-1:25, Colorado’s “Post-election audit” rule.

Voting Systems Used

Almost all counties in Colorado use hand-marked paper ballots and optical scanners, with ballot marking devices for accessibility. All registered voters receive a mail ballot and ballots are tabulated by batch-fed optical scanners. One county hand counts in lieu of using optical scanners. For the most up to date information please visit Verified Voting’s Verifier.

For an explanation on the types of voting equipment used, click here.

Audit Comprehensiveness

Colorado utilizes a risk-limiting audit with procedures and contest selections to be established by the secretary of state, although all contested races are eligible. Colo. Rev. Stat. §1-7-515(2)(a).

Ballots included in the RLA include all in-person and accepted mail ballots, and any accepted provisional and property owner ballots, which have been verified and accepted on or before the ninth day after election day, that the county opts to include. 8 Colo. Code Regs. § 1505-1:25.2.2(e). The one county that hand counts its ballots is exempt from the audit. ​​See Colo. Rev. Stat. §1-7-515(2)(b); see also Colorado Secretary of State, “Risk-Limiting Audit (RLA) FAQs: Q3. What kind of risk-limiting audits are there?”. For the purposes of the database, we consider only machine-tabulated ballots as subject to audit in Colorado. Note that for the Post-Election Audits map this translates to a broader classification of “Some, But Not All” ballots subject to audit, although Colorado audits the overwhelming majority of its ballots.

Transparency

At least two canvass board members must observe at least the first round of the RLA. 8 Colo. Code Regs. § 1505-1:25.2.2(c)(1). The designated election official, members of their staff, and other duly appointed election judges may assist with the risk-limiting audit. Members of the public (watchers) are allowed to observe the audit. See 8 Colo. Code Regs. § 1505-1:8. Audit results are posted on the secretary of state’s official website.

Audit Counting Method

In counties conducting comparison audits, audit boards examine each randomly selected ballot card and report voter markings or choices in all contests. 8 Colo. Code Regs. § 1505-1:25.2.3(a)(1). In counties conducting ballot polling audits, audit boards examine and report the voter markings or choices in only the target contest on each randomly selected ballot card in a form approved by the secretary of state. 8 Colo. Code Regs. § 1505-1:25.2.3(a)(2).

Type Of Audit Units

Colorado audits individual ballots. Counties that use voting systems capable of exporting Cast Vote Records (CVRs) must conduct a comparison audit, while counties that use voting systems incapable of exporting CVRs must conduct a ballot polling audit. 8 Colo. Code Regs. § 1505-1:25.2.1(a–b). Because all counties currently conducting post-election audits in the state use voting systems capable of exporting CVRs, all counties currently conduct ballot comparison audits. Colorado Secretary of State, “Risk-Limiting Audit (RLA) FAQs: Q3. What kind of risk-limiting audits are there?”. The one county that hand counts its ballots is exempt from the audit. ​​See Colo. Rev. Stat. §1-7-515(2)(b).

Contests & Issues Audited

In a general or coordinated election, the secretary of state selects, as “target contests,” at least one statewide contest (or other contests if there is no statewide contest), and, for each county, at least one other contest, taking into account criteria listed in 8 Colo. Code Regs. § 1505-1:25.2.2(j).

In a primary election, the secretary of state selects at least one contest of each major political party in each county. 8 Colo. Code Regs. § 1505-1:25.2.2(j) (requirement that the contest be countywide stricken in 2023). The risk limit is binding on these target contests. Moreover, in counties that conduct comparison audits (currently, all participating counties), the audit board must examine each randomly selected ballot card and report the voter selections in all contests that appear on the ballot card. 8 Colo. Code Regs. § 1505-1:25.2.3(a).

Addressing Discrepancies

The RLA will continue until the risk limit for the target contests is met or until a full hand count results. 8 Colo. Code Regs. § 1505-1:25.2.3(c). If the county audit reports reflect that the risk limit has not been satisfied in a target contest, the secretary of state will randomly select additional ballots for audit. Id.

The secretary of state compares audit boards’ reports of the audited ballot cards to the corresponding CVRs and posts the results of the comparison on the secretary of state’s website. 8 Colo. Code Regs. § 1505-1:25.2.3(c). Before certifying official results, all participating counties that conduct a ballot comparison audit must manually adjust the preliminary results to account for discrepancies identified in the risk-limiting audit if directed by the secretary of state. 8 Colo. Code Regs. § 1505-1:10.4.

For recount laws, please visit our Recount Law Database.

Timeline

The secretary of state selects the target contests to be audited by the Friday after Election Day. 8 Colo. Code Regs. § 1505-1:25.2.2(j).The random seed is established and the audit sample generated in a public meeting on the thirteenth day after election day. 8 Colo. Code Regs. § 1505-1:25.2.2(i). Each county audit board must complete its report by the day before the canvass deadline. 8 Colo. Code Regs. § 1505-1:25.2.3(d). Upon reviewing the audit boards’ reports, the secretary of state may direct county clerks to conduct additional audit rounds, a random audit, a full hand count, or other action and may instruct a county to delay canvass until it completes any additional audit or other action. 8 Colo. Code Regs. § 1505-1:25.2.3(e); see also 8 Colo. Code Regs. § 1505-1:10.4.

In jurisdictions that conduct ranked choice voting, election officials are likewise required to “audit each ranked voting race before the canvass board certifies official election results in a manner which will not interfere with the audit required by statute. 8. Colo. Code Regs. § 1505-1:26.9.

Binding On Official Outcomes

As applicable, the secretary of state may instruct a county to delay canvass until it completes any additional audit or other action. 8 Colo. Code Regs. § 1505-1:25.2.3(e). If the audit leads to a recount, the results of the recount are binding. See Colo. Rev. Stat. §1-7-515(5)(b); see also 8 Colo. Code Regs. § 1505-1:10.4.

Oversight & Conduct

The secretary of state oversees risk-limiting audits by establishing rules for administration and enforcement. Colo. Rev. Stat. §1-7-515(4). County officials and audit boards conduct the audit.

Ballot Protection

Counties must submit detailed plans to the secretary of state about transportation of election equipment and ballots. See 8 Colo. Code Regs. § 1505-1:20.1; see also § 1505-1.20.5.4. Designated election officials are responsible for preserving election records for at least 25 months after an election or until time has expired for which the record would be needed in any contest proceedings, whichever is later. Colo. Rev. Stat. § 1-7-802.

Additional Targeted Samples

Colorado statutes do not provide for targeted samples. However, Rule 25 states that the secretary of state “will review the audit board’s report and may direct the county clerk to conduct additional audit rounds, a random audit, a full hand count, or other action.” 8 Colo. Code Regs. § 1505-1:25.2.3(e). Therefore, other actions could include targeted hand counts.

Resources

8 Colo. Code Regs. § 1505-1:25 (Post-election audit rule)

Colo. Rev. Stat. §1-7-515 (Risk-limiting audit statute)

8 Colo. Code Regs. § 1505-1:8 (Poll watcher rule)

8 Colo. Code Regs. § 1505-1:10 (Canvassing and recount rule)

8 Colo. Code Regs. § 1505-1:20 (County security procedures rule)

8. Colo. Code Regs. § 1505-1:26.9 (Ranked choice voting)

Colo. Rev. Stat. § 1-7-802 (Preservation of election records statute)

Last updated: September 27, 2023