The short answer
About 3 years: the certificate holder cannot apply for the treasurer's deed until after August 1 of the third calendar year following the tax lien sale
How the clock works
Redemption may be made at any time before a treasurer's deed is executed, so the practical window runs past the three-year mark and into the Article 11.5 process. Once a deed application is pending, the owner must file an intent to redeem with the treasurer no later than seven calendar days before the scheduled public auction, then pay the amount on the redemption statement while it is in effect, and must redeem the entire property. The auction itself is set 30 to 60 calendar days after the treasurer mails the notice of public auction. A separate rule lets an owner who was under a legal disability when a tax deed was executed under Article 11 redeem within nine years of the deed being recorded, at 15 percent per year plus the present value of any improvements.
Who can redeem
The owner, or the owner's agent, assignee, or attorney, any person holding a legal or equitable claim in the property, and the holder of a tax sale certificate. An undivided interest can be redeemed by paying a ratable share before a deed application is pending, but once the Article 11.5 process starts the owner must redeem the entire property. Junior lienors do not redeem the property itself, but those who file a claim for overbid money within eight business days after the auction are paid from the overbid.
What the owner pays to redeem
The taxes, delinquent interest, and costs for which the lien was sold, plus redemption interest from the date of sale at the rate in force, plus every subsequent tax the holder paid and had endorsed on the certificate with interest at the same rate, plus the statutory fees the purchaser paid. Portions of months count as whole months. The premium the investor bid above the taxes is not part of the redemption amount and is not returned.
How your interest accrues
Redemption interest runs from the date of sale on the taxes, delinquent interest, and costs for which the lien sold, and on any subsequent taxes the holder pays and has endorsed on the certificate. Portions of a month count as a whole month. The rate is not fixed in the statute. C.R.S. 39-12-103(3) sets it at nine percentage points above the Kansas City Federal Reserve Bank discount rate, rounded to the nearest full percent, and the commissioner of banking establishes it each September 1 to take effect that October 1. The rate effective October 1, 2026 is 13 percent. There is no minimum-return floor in the redemption statute. The 8 percent floor investors sometimes see quoted sits in C.R.S. 39-12-111, which covers county repayment when a lien was wrongfully sold on land that owed no tax, and it does not apply to ordinary redemptions.
How the bidding works
Colorado does not bid the interest rate down. Every certificate sold in a given rate year earns the same statewide rate, and competition happens through premium bidding instead. The lien opens at the taxes, delinquent interest, and fees due, and the bidder who pays the largest amount in excess wins. That excess is credited to the county general fund. It earns no interest, it is not added to the redemption amount, and it is not refunded when the owner redeems, so an aggressive premium directly reduces the investor's yield. Treasurers may also set a minimum total below which they will not accept competitive bids.
If the certificate is never redeemed
After August 1 of the third calendar year following the tax lien sale, the lawful holder of the certificate of purchase may apply to the treasurer for a treasurer's deed. The treasurer then sells the property at a public auction, and the winning bidder receives a certificate of option for a treasurer's deed. A lawful holder who did not win may repurchase that certificate by filing a notice of intent within three business days and paying the winning bid's excess over the debt, with interest, by noon on the eighth business day. Title vests at the close of the eighth business day after the auction, and the treasurer then records the deed. On and after July 1, 2024 a treasurer may not issue a deed under Article 11, which is how Colorado answered Tyler v. Hennepin County on owner equity, and the Article 11.5 that governs now is the version SB 26-144 reenacted effective June 1, 2026.
A redeemed certificate, plus your accrued interest, is what makes the wait profitable; see how redemption periods work across states. An unredeemed certificate is instead your path to the property through a tax deed sale, which still does not convey marketable title on its own, so budget for a quiet title action.
Verified Oct 12, 2026 against Colorado statutes.
Tax Sale Atlas publishes educational information about public tax sale processes. This is not legal, financial, or investment advice. Rules, dates, and fees change; confirm with the office that runs the sale before you bid.