Original ballot
Amendment 01 combined several fiscal and election rules in one question.
Official wording read; the scanned booklet not reviewed
Initial draft, not independently reviewedElection pending: November 3, 2026
TABOR: voter control, public revenue, and Colorado's ballot choices
Understand the rules behind Colorado's recurring debates about taxes, refunds and public spending, and the evidence needed to assess their results.
This page gives no recommendation for or against any measure. A sourced first draft: the research summary has not had a reviewer sign off, and several sources were read at abstract level only (marked below). Prepared October 26, 2026.
The policy in plain language
Colorado voters adopted the Taxpayer's Bill of Rights, known as TABOR, in 1992. Its rules include voter approval for tax increases and a limit on how much revenue government may keep. Revenue above the applicable limit generally has to be returned unless voters allow it to be kept. Setting a tax rate and allowing the government to keep revenue are two different questions. S1
Referendum C, approved in 2005, let the state keep all the revenue it collected for fiscal years 2005-06 through 2009-10. It also set an ongoing adjusted cap that grows from fiscal year 2007-08 revenue. Revenue above that cap is still subject to refunds. The limit grows with inflation and population. These are state mechanics; local governments are treated separately. S1
Official 1992 and 2005 results, checked October 26, 2026 in the Colorado Secretary of State's Historical Elections Database: 1992 Amendment 01, 812,308 yes and 700,906 no out of 1,513,214 votes on the question (53.68 percent yes) S7. The same database lists 83,952 blank votes and 1,597,166 ballots cast; those are different denominators. 2005 Referendum C, 600,222 yes and 552,662 no out of 1,152,884 votes (52.06 percent yes) S8.
Article X, section 20 (the TABOR text): we read the current official edition, the 2026 Colorado Constitution published by the Office of Legislative Legal Services, on October 26, 2026, and keep a dated copy. Its opening rule says the preferred interpretation is to "reasonably restrain most the growth of government." A reader should open the official text for any legal detail: olls.info, 2026 edition. This page quotes only that sentence and summarizes the rest in plain words. We read these totals in the state database in a browser. The certification statements on the original 1992 and 2005 abstract-of-votes scans have not been read (see "What we do not yet know").
What does that look like in action?
Invented teaching numbers, not Colorado figures and not a calculator.
Suppose revenue subject to a limit is $110 and the limit is $100. With no voter authorization, the $10 excess is refundable. If voters instead authorize keeping revenue up to $108, then $8 can be kept and $2 is still refundable. Neither case changes any tax rate.
A government can have revenue above a legal cap and still have unmet needs. A formula "surplus" does not measure whether every service is paid for. In the other direction, an unmet need does not show that a given appropriation will fix it. Both the budget rule and the proposed use deserve a look.
Intent, implementation, and outcomes
Three lanes run side by side. Each card names its source and how far to trust it. A text version of the same information follows the lanes.
Intent
- 1992 Ballot question asks voters to require voter approval for certain tax increases and debt, restrict some taxes, limit the rate of growth in state and local spending, allow more initiative elections, and mail information to voters. Official ballot text S7
- Constitutional language favors restraining the growth of government. Whether that is desirable is a value judgment. Official 2026 text read S2
Implementation
- 1992 Voters adopt TABOR. Official result S7
- 2005 Voters approve Referendum C. The question covered five years of keeping excess revenue and ongoing retention under a defined cap afterward. Official ballot text S8
- FY 2005-06 to 2009-10 Referendum C retention period. Official explanation S1
- FY 2010-11 onward Ongoing Referendum C cap. Official explanation S1
- September 8, 2025 Colorado Supreme Court holds Lakewood's ordinances were new taxes imposed without required voter approval (MetroPCS v. Lakewood). Court opinion S10
- June 2026 HB26-1419 becomes law, tying a conditional over-refund calculation to federal tax changes and limiting how much can be offset in a single future year. Enacted summary read; check the signed act before legal use S9
Outcomes
Ordered by publication year. A study's evidence covers a different period, shown on each card.
- 2007 Martell and Teske: reports pressure toward earmarking, privatizing and shifting responsibilities during downturns. Peer reviewed; abstract level S12
- 2012 St. Clair: evidence of higher revenue and spending volatility in Colorado local-government data. Peer reviewed; abstract level S11
- 2015 Resnick, Brown and Godshall (Lincoln Institute): says TABOR forced fairly significant redistribution of school funding in its simulation; the paper says its findings did not get detailed staff review. Working paper; sentence read on page 33 S13
- 2018 Eliason and Lutz, Journal of Public Economics: no detectable effect on total taxes or spending in their comparison of Colorado with other states (evidence covers 1977 to 2012). Peer reviewed; abstract level for the final article S3
- 2026 Jansen and Moore (Texas A&M research center): emphasizes limits on non-exempt revenue and adaptation through Referendum C and exempt activity. Research report; peer review not established S4
Text version of the timeline
| When | Lane | What | Status |
|---|---|---|---|
| 1992 | Intent / Implementation | Amendment 01 asked voters to adopt TABOR and passed | Official source |
| 2005 | Implementation | Referendum C passed | Official source |
| FY 2005-06 to 2009-10 | Implementation | Retention period | Official explanation |
| FY 2010-11 onward | Implementation | Ongoing cap | Official explanation |
| 2007, 2012, 2015, 2018, 2026 | Outcomes | Research findings listed above; they measure different things | Abstract level or report; see lane |
| September 8, 2025 | Implementation | Lakewood ruling | Court opinion |
| June 2026 | Implementation | HB26-1419 enacted | Summary read |
| November 3, 2026 | Pending | Related measures go to voters | Pending, not decided |
Still to build, not yet verified timeline entries: original sponsors and campaign history; Amendment 23; enterprise legislation; local retention votes; Propositions CC and HH; other court decisions.
Interactive timeline
Pick an event to read it with its sources. Switch the card between what the ballot or law said it was for and what happened. A stated purpose is attributed to its source; it is not a claim about anyone's motives, and an event that comes after another does not show the first caused it. Without JavaScript, the lanes and the table above give the same chronology.
The interactive timeline needs JavaScript. The lanes and the text table above list the same events.
Evidence cards
Each card summarizes one piece of evidence and has its own link to the underlying source. The cards are static; they do not drive the lanes above.
Referendum C
The ballot offered both temporary and ongoing retention authority.
Official mechanism
Real allocations
In FY 2024-25 the state kept $3,690.7 million under Referendum C: $1,248.8 million each to K-12 and health care, $1,188.6 million to higher education, $4.0 million to volunteer firefighter retirement and $0.5 million to transportation. Staff caution that much of this prevented cuts rather than adding services.
Historical accounting, not a measured service effect
Aggregate effects
One peer-reviewed study finds no detectable effect on total taxes or spending.
Abstract level
Volatility
One peer-reviewed study reports greater local revenue and spending volatility.
Abstract level
Fees and enterprises
Fee revenue of government enterprises falls outside the limit, which changes fiscal incentives. A 2022 staff memo is the explanation; its totals are older than 2026.
Official explanation, historical
Enforcement
The Colorado Supreme Court voided two Lakewood ordinances as taxes imposed without a vote.
Court holding
Latest baseline
The September 2026 forecast revises earlier expectations. See the dated forecast below.
Forecast, not realized revenue
What the research currently says
These studies measure different things over different periods. Taxes and spending in total, volatility, and who pays school property taxes are not the same outcome, and they should not be averaged into one verdict.
| Study | Type and access | Finding and limits |
|---|---|---|
| Eliason and Lutz, 2018, Journal of Public Economics 166:115-144 S3 | Peer reviewed. Abstract and indexed material read; full text not obtained. | No detectable overall tax or spending effect in the historical comparison (state and local data, 1977 to 2012). Not proof of no effect on services, distribution or any single fund. One state limits generalization. The authors' December 2017 manuscript, which is not the final article, concludes in its own words "We find no evidence that TABOR influenced budget outcomes." We have not confirmed the final article uses the same wording. |
| Martell and Teske, 2007, Public Administration Review 67:673-687 S12 | Peer reviewed. Abstract only. | Reports incentives to earmark, privatize and shift responsibilities when limits bind. Not an estimate for 2026. |
| St. Clair, 2012, Public Budgeting & Finance 32(3):61-78 S11 | Peer reviewed. Abstract only. | Finds higher revenue and expenditure volatility. The abstract does not allow checking the method. |
| Resnick, Brown and Godshall, 2015, Lincoln Institute working paper WP15PR1 S13 | Working paper. Page 33 sentence on redistribution confirmed; full paper otherwise not reviewed. | Reports TABOR forced fairly significant redistribution of school funding, an effect in the authors' simulation, not a directly observed world without TABOR. It says its findings did not get detailed staff review. We could not identify a DOI for it; WP15PR1 is a working-paper number, not a DOI. |
| Jansen and Moore, 2026, Texas A&M Private Enterprise Research Center S4 | Research report. Repository abstract read; peer review not established. | Focuses on non-exempt revenues and adaptation. Review its methods before adopting conclusions. |
Published evidence includes both fiscal-management and volatility costs and a finding against a large drop in total government activity during the period studied. Neither settles whether direct voter control is worth it, and none alone establishes TABOR's net effect today.
Connection to the November 2026 ballot
The official 2026 Blue Book connects TABOR to four measures. All four are proposals; none has been decided. S5
- Proposition NN: retention of revenue. The Blue Book separates about $4.6 billion of added first-year capacity from about $500 million in expected actual retention. These are estimates, not receipts.
- Amendment 87: graduated income taxation and related revenue.
- Proposition 136: a statutory rate ceiling.
- Proposition 137: dedicated sporting-goods sales-tax revenue and exemption from the limit.
WarningTwo vintages of numbers: Blue Book estimates and the later forecast are kept separate.DetailsHide details
Two vintages of numbers: the Blue Book (September 10, 2026) gives refund estimates for budget years 2026-27 and 2027-28 and says no forecast was available beyond that. The Legislative Council's September 2026 forecast, shown below, projects the current-law baseline through 2028-29. The baseline is not a re-estimate of any measure, so its figures are not swapped into the Blue Book's measure estimates. Household refund figures anywhere in the guide are estimates.
The Blue Book also says it is uncertain how a conflict would be resolved if 87 and 136 both pass. Do not assume an outcome. These descriptions are short; use each measure page and the Blue Book for the exact wording. Numbers from the September 10 Blue Book are dated official estimates and are kept as published.
Questions to bring to any TABOR-related proposal
- Does it change a rate, a revenue limit, an exemption, an allocation, or several of these?
- What happens under current law if it fails?
- Is a dollar figure a legal maximum, a forecast, an appropriation or actual spending?
- What uses are required and what is left to lawmakers, now and later?
- Who gets refunds or services, and how is that measured?
- What reporting would let anyone compare what was promised with what was delivered?
Dated forecast: September 2026
WarningForecast vintage September 2026: a baseline under current law, not a measure estimate.DetailsHide details
Forecast vintage September 2026 (Legislative Council Staff). Fiscal 2025-26 is preliminary and later years are estimates. Nominal millions of dollars. This is a baseline under current law, not what any measure would do, and not money already collected.
| Fiscal year | Status | Covered revenue | Applicable cap | Above or below cap | Refunded after listed adjustments |
|---|---|---|---|---|---|
| 2025-26 | Preliminary | 19,835.4 | 20,011.3 | -175.9 | 0.0 |
| 2026-27 | Forecast | 21,314.9 | 20,488.1 | 826.8 | 463.7 |
| 2027-28 | Forecast | 21,886.3 | 21,307.6 | 578.7 | 490.7 |
| 2028-29 | Forecast | 22,577.1 | 21,925.6 | 651.5 | 651.5 |
Gross excess is not always the refund owed, because the table lists adjustments for earlier over-refunds. Dividing the excess by population does not give a household check. S16 Download this table as CSV
What we do not yet know
This draft does not establish TABOR's net effect on economic growth, school quality, inequality, voter understanding or administrative cost. It does not blame Colorado's fiscal condition on TABOR alone: recessions, population change, federal money, other laws and local choices all matter.
Open work before this could be called a reviewed study: read the certification statements on the original 1992 and 2005 abstract-of-votes scans and check the 1992 database wording against the ballot scan (the state's file host blocks automated download, so a person has to fetch them); check the latest Legislative Council forecast and the fiscal notes for each measure; read the full published text of Eliason and Lutz (2018), St. Clair (2012) and Martell and Teske (2007), since only abstracts were read; build a consistent yearly series of covered revenue, cap and refunds; find research that disagrees; and get a public-finance or methods reviewer. No reviewer has signed off.
Sources
Links checked October 26, 2026. No source files were archived. "Read" means the retrieved text or named sections, not a full audit.
- Colorado Legislative Council Staff, TABOR handbook. Official explanation; read. content.leg.colorado.gov
- Colorado Constitution, article X, section 20, 2026 edition, Office of Legislative Legal Services. Official text; read October 26, 2026; dated copy kept. olls.info (gateway: 2026 download page)
- Eliason, Paul and Byron Lutz (2018), Journal of Public Economics 166:115-144. Peer reviewed; abstract level. DOI
- Jansen, Dennis W. and Tyler I. Moore (2026), Texas A&M Private Enterprise Research Center. Report; peer review not established. Repository record
- Colorado Legislative Council, 2026 State Ballot Information Booklet (Blue Book), September 10, 2026. Official ballot analysis. PDF
- Legislative Council Staff, The TABOR Revenue Limit (2022 page). Landing page checked only. Page
- Colorado Secretary of State, Historical Elections Database, 1992 Amendment 01, contest 24859. Wording and totals read in a browser October 26, 2026. Record
- Colorado Secretary of State, Historical Elections Database, 2005 Referendum C, contest 6026. Wording and totals read in a browser October 26, 2026. Record
- Colorado General Assembly, HB26-1419, enacted summary. Bill page
- Colorado Supreme Court, MetroPCS California, LLC v. City of Lakewood, 2025 CO 53, No. 24SA178. Opening and closing analysis read. Opinion
- St. Clair, Travis (2012), Public Budgeting & Finance 32(3):61-78. Abstract only. DOI
- Martell, Christine R. and Paul Teske (2007), Public Administration Review 67:673-687. Abstract only. DOI
- Resnick, Phyllis, Charles Brown and Deborah Godshall (2015), "Measuring the Impact of Tax and Expenditure Limits on Public School Finance in Colorado," Lincoln Institute working paper WP15PR1. Page
- Legislative Council Staff, Report on Referendum C Revenue and Spending, October 15, 2025. PDF
- Legislative Council Staff, State Government Enterprises, August 30, 2022. Historical explanation. PDF
- Legislative Council Staff, September 2026 Economic and Revenue Forecast, TABOR outlook, Table 10, printed page 36. Forecast, not realized revenue. PDF
Related: all Ballot Case Studies, Research, Civics & History, the Voter Guide and Search. Review status: initial draft, not independently reviewed. Source copies: we keep private dated copies of the official documents cited here; a copy is not a review.