Usually not. First, second, and third DUI offenses in Colorado are misdemeanors. A DUI becomes a felony in three situations: it is your fourth or subsequent alcohol-related driving conviction, which is a class 4 felony under C.R.S. 42-4-1301; the impaired driving caused serious bodily injury, charged as vehicular assault and also a class 4 felony; or it caused a death, charged as vehicular homicide and a class 3 felony carrying 4 to 12 years.

The fourth-offense rule contains a detail that catches people off guard. Colorado has no lookback period for felony DUI. A conviction from 1998 counts exactly the same as one from last year, and out-of-state convictions and DWAI convictions count too.

When Does a Fourth DUI Become a Felony?

The felony DUI statute was created in 2015. It applies when a person has three prior qualifying convictions at any point in their lifetime, making the fourth offense a class 4 felony.

What counts as a prior:

  • DUI convictions
  • DWAI convictions, driving while ability impaired
  • DUI per se convictions
  • Out-of-state equivalents
  • Certain other qualifying vehicular offenses

There is no time limit. Colorado’s five-year lookback applies to certain misdemeanor sentencing enhancements, not to the felony trigger.

One important limitation that gets missed: the statute requires prior convictions, not arrests or pending cases. If you have several DUI charges pending but none resolved, a new charge may initially be filed as a misdemeanor. The sequencing of your prior case resolutions genuinely matters, and it is worth having counsel examine.

What Are the Penalties for Felony DUI in Colorado?

A class 4 felony carries a presumptive range of 2 to 6 years in the Department of Corrections with a mandatory 3-year parole period if the court imposes a prison sentence. With extraordinary aggravating circumstances, such as being on parole, probation, or bond for another felony at the time, the range increases to 4 to 12 years.

Prison is not automatic. But if the court grants probation, Colorado law requires a mandatory jail component. Since a 2017 amendment, a felony DUI probation sentence must include one of the following:

  • 90 to 180 days in county jail; or
  • 120 days to 2 years in county jail through an alternative sentencing program such as work release or education release

Note the trade-off: choosing work release to keep your job means a longer minimum, 120 days instead of 90. During the mandatory 90-day period you are not eligible for good-time deductions or trustee status, though you do receive credit for time served before conviction.

Other mandatory probation conditions:

  • 48 to 120 hours of useful public service
  • At least 90 days of continuous alcohol monitoring
  • A Level II education or treatment program
  • Ignition interlock during probation, and as a parole condition for felony DUI offenders
  • Probation term typically 2 to 6 years

A fourth DUI conviction also designates you a persistent drunk driver, which carries its own reinstatement requirements.

What Are the Misdemeanor DUI Penalties?

  • First offense: commonly probation with alcohol education, fines, useful public service, and license consequences
  • Second offense: mandatory minimum 10 days in jail
  • Third offense: mandatory minimum 60 days in jail

The jump from a 60-day misdemeanor minimum to felony exposure on the fourth offense is the steepest escalation in Colorado’s traffic code, and it is the reason a third DUI should be defended as though the fourth is already in view.

What Is the Linnebur Defense?

This is the most important development in Colorado felony DUI law, and many defendants have never heard of it.

In Linnebur v. People (2020), the Colorado Supreme Court held that prior convictions in a felony DUI prosecution are elements of the offense rather than sentencing factors. That means the prosecution must prove your three prior convictions to the jury, beyond a reasonable doubt, not merely establish them at sentencing by a lower standard.

Why this matters in practice:

  • The State must produce admissible, properly authenticated records of each prior conviction
  • Identity must be established, meaning the State must prove that the person in that old judgment is you
  • Old convictions from other states, or from decades ago, frequently have documentation problems
  • If the State cannot prove three qualifying priors to a jury, the felony fails and the case is a misdemeanor

Records get lost. Out-of-state judgments do not always match Colorado’s statutory equivalents. Pulling the complete file on every prior, not just a docket printout, is standard work in a competent felony DUI defense.

How Do You Defend a Colorado DUI Charge?

The defenses are the same at every level, but the stakes make them worth more in a felony case.

Challenge the stop. Police need reasonable suspicion for the traffic stop. An unlawful stop can suppress everything that followed.

Challenge the blood or breath evidence. This is usually the strongest ground:

  • Warrant requirements and the validity of consent for a blood draw
  • Express consent compliance under C.R.S. 42-4-1301.1, including whether the advisement was properly given
  • Chain of custody, preservatives, and storage of the sample
  • Instrument calibration and certification records for breath testing
  • Timing and retrograde extrapolation, since a draw two hours later does not establish your level while driving

Challenge the priors. Under Linnebur, this is an element the State must prove.

Challenge impairment for drug cases. THC blood levels do not correlate reliably with impairment at the time of driving, and metabolites persist for days.

Address the DMV case separately. The Department of Revenue runs its own express consent revocation proceeding on a faster timeline and a lower standard of proof. You can win in court and still lose your license. The hearing request deadline is short, and missing it forfeits the hearing.

Colorado Felony DUI FAQs

Do out-of-state DUIs count toward the fourth offense?

Yes. Convictions from other states count, provided they are substantially similar to a Colorado offense.

Is there a lookback period for felony DUI in Colorado?

No. Prior DUI convictions count for life for purposes of the felony threshold.

Will I definitely go to prison for a fourth DUI?

Not necessarily. Probation is available, but it carries a mandatory jail component of at least 90 days.

Can a felony DUI be sealed?

Colorado does not permit sealing for most felony convictions of this type. Our guide on record sealing timelines covers eligibility.

Does a DWAI count as a prior?

Yes. DWAI convictions count toward the three priors that trigger felony treatment.

Your First Moves After a Fourth DUI Arrest

Two clocks are running, and the shorter one is administrative.

  1. Request your DMV hearing immediately. The deadline is short and missing it forfeits the hearing entirely
  2. Say nothing about how much you drank. Roadside admissions are the most damaging evidence in these cases
  3. Pull the complete records on every prior conviction, since under Linnebur these are elements the State must prove to a jury
  4. Get the full blood draw file, including the warrant, advisement, and lab documentation
  5. Begin treatment or evaluation now. Pre-sentencing effort measurably affects whether a court grants probation
  6. Ask counsel about alternative sentencing early, since the 90-day versus 120-day trade-off affects your employment

Flatiron Legal Advisors defends impaired driving charges at every level through our DUI defense and Colorado criminal defense teams. For related reading, see our guides on steps to take after a Colorado DUI arrest, DUI causing serious injury, and ignition interlock requirements.

Schedule a confidential consultation today, because the DMV deadline will not wait.

Reviewed by the Flatiron Legal Advisors criminal defense team. This article is general information, not legal advice for your specific case.