There is no single number for how long the average life sentence lasts in the United States, because “life sentence” covers very different legal realities. For state prisoners released after a murder conviction in 2018, the average time served was roughly 17.8 years.1Bureau of Justice Statistics. Time Served in State Prison, 2018 But that figure only counts people who got out. It leaves out everyone still behind bars and everyone serving life without the possibility of parole, who are expected to die in custody. A life sentence with parole today typically means 15 to 30 years or more before any chance of release. A life sentence without parole usually means the rest of the person’s life. As of 2024, nearly 195,000 people in the United States were serving some form of life sentence.
Parole or No Parole Decides Almost Everything
The single biggest factor in how long a life sentence actually lasts is whether the sentence carries the possibility of parole.
Life With Parole
A sentence of life with parole sets a mandatory minimum number of years the person must serve before becoming eligible for a parole hearing. Eligibility is not release. It only means the inmate can appear before a parole board that has the power to grant or deny freedom. If the board says no, the person stays locked up until a future hearing, often years later.
Life Without Parole
Life without parole removes the parole mechanism entirely. The person is expected to die in prison. The only realistic paths out are a successful appeal overturning the conviction, executive clemency, or compassionate release for severe medical conditions.2Northwestern University Law Review. Worthless Checks? Clemency, Compassionate Release, and the Finality of Life Without Parole Each of those is exceedingly rare. As of 2024, more than 56,000 people in U.S. prisons were serving life without parole, a 68 percent increase since 2003.
Virtual Life Sentences
Some defendants receive a term of years so long it functions as life without parole. A judge might impose 150, 200, or 400 years. The U.S. Sentencing Commission treats any federal sentence of 470 months (just over 39 years) or longer as a de facto life sentence for research purposes.3United States Sentencing Commission. Life Sentences in the Federal System More than 41,000 people were serving virtual life sentences in state and federal prisons as of 2024.
How Many Years People Actually Serve
Time served on life sentences has been climbing. People admitted with life sentences in 1991 served an average of about 21 years; those admitted in 1997 served an average of 29 years. That is a 37 percent jump over six years, driven by states raising parole eligibility thresholds and parole boards becoming more reluctant to grant release.
The Bureau of Justice Statistics figure of roughly 17.8 years for state prisoners released after a murder conviction in 2018 is the most frequently cited number, but it is a poor measure of life sentences overall.1Bureau of Justice Statistics. Time Served in State Prison, 2018 It captures only people who were released, so it excludes every lifer still incarcerated and everyone serving life without parole. The true average across all people with life sentences is considerably higher, because most of them have not been released and many never will be.
In practical terms: a life-with-parole sentence today usually means at least 15 to 30 years before a first realistic chance at release, and many people serve much longer than their minimum. A life-without-parole sentence means the person will almost certainly die in custody.
Parole Eligibility Varies Widely by State
Every state sets its own rules for when a lifer becomes parole-eligible, and the differences are dramatic. Some states allow parole hearings after as few as 7 years. Others require 40 years or more. Many states have raised their minimums over the past few decades, so the year the crime was committed can matter as much as the state where it happened.
A few examples show the range. In Georgia, someone convicted of a crime committed before 1995 becomes eligible for parole after 7 years; if the same crime happened after 2006, the minimum jumps to 30 years. In Colorado, parole eligibility for a life sentence went from 10 years for crimes before 1977 to 40 years for crimes after 1985, and crimes committed after 1990 carry no parole eligibility at all. Maryland requires 15 years for crimes committed before 2021 and 20 years for those committed afterward. Minnesota increased its minimum from 17 to 30 years in 1989.
The direction is consistent. Legislatures keep pushing eligibility dates further out, which means people sentenced to life today will generally serve far more time than someone who received the same sentence a generation ago.
Eligibility Is Not the Same as Release
Reaching the parole eligibility date is the beginning of a long, uncertain process. A parole board weighs the details of the original crime, the person’s criminal history, their disciplinary record in prison, participation in educational or vocational programs, their plan for housing and work after release, and input from victims or their families.4U.S. Parole Commission. Frequently Asked Questions
Denial is more common than release, especially at first hearings. In some states, a lifer being released at the first hearing is virtually unheard of. When the board denies parole, it schedules a future hearing, often several years out. Repeated denials can effectively convert a life-with-parole sentence into life without parole in practice, even though the legal label does not change.
Federal Life Sentences Have No Parole
The federal system runs differently. The Sentencing Reform Act of 1984 eliminated parole for all federal crimes committed after November 1, 1987.5United States Department of Justice. About the United States Parole Commission A federal life sentence imposed today is effectively life without parole. There is no parole board to petition and no minimum after which release becomes possible through the usual parole process. The only realistic exits are a presidential pardon, a successful appeal, or compassionate release under 18 U.S.C. ยง 3582.6Office of the Law Revision Counsel. 18 U.S. Code 3582 – Imposition of a Sentence of Imprisonment
A small number of federal prisoners still fall under the old parole system because they committed their offenses before November 1, 1987. For them, parole eligibility for a life sentence arrives after 10 years.4U.S. Parole Commission. Frequently Asked Questions
Good-Time Credits Don’t Shorten a Life Sentence
In the federal system, prisoners can earn up to 54 days per year of credit for good behavior, which shortens the time they actually serve. People serving life sentences are specifically excluded. The statute limits good-time credit to prisoners serving a term “other than a term of imprisonment for the duration of the prisoner’s life.”7Office of the Law Revision Counsel. 18 U.S. Code 3624 – Release of a Prisoner State rules vary, but many states similarly bar lifers from earning time off, or allow credits to reduce only the wait until parole eligibility rather than the life sentence itself.
The Narrow Exits: Compassionate Release and Clemency
For someone serving life without parole, compassionate release is the most realistic legal avenue, though the bar is intentionally high. In the federal system, a court can reduce a life sentence if it finds “extraordinary and compelling reasons,” which generally include terminal illness, severe physical or mental incapacitation, advanced age combined with serious health decline (at least 65, with at least 10 years or 75 percent of the sentence served), or the death or incapacitation of the sole caregiver for the person’s minor children.6Office of the Law Revision Counsel. 18 U.S. Code 3582 – Imposition of a Sentence of Imprisonment The inmate must first ask the Bureau of Prisons to file a motion, or wait 30 days after making that request before filing their own motion with the court.
A separate safety valve applies to people sentenced under the federal three-strikes law: if the person is at least 70 and has served at least 30 years, the Bureau of Prisons director can determine they are no longer dangerous, and the court can then reduce the sentence.
Executive clemency is the other option and is vanishingly rare. A presidential pardon or commutation can override any federal sentence, and governors have similar power over state sentences. In practice, clemency for lifers is granted to a tiny fraction of those who apply. The process involves extensive background investigation, recommendations from the original sentencing judge and prosecutors, and a discretionary decision by the executive. Most applications are denied, and many are never acted on at all.
A Different Rule for Juveniles
Life sentences work differently for people who committed their crimes as minors. In Miller v. Alabama (2012), the Supreme Court held that mandatory life-without-parole sentences for juvenile homicide offenders violate the Eighth Amendment.8Justia Law. Miller v. Alabama, 567 U.S. 460 (2012) Montgomery v. Louisiana (2016) made that rule retroactive, so people already serving mandatory juvenile LWOP sentences could seek resentencing or parole consideration.9Justia Law. Montgomery v. Louisiana, 577 U.S. 190 (2016) Jones v. Mississippi (2021) narrowed those protections, holding that a sentencing judge does not need to make a specific finding that a juvenile is “permanently incorrigible” before imposing life without parole; a discretionary process that considers youth is enough.10Justia Law. Jones v. Mississippi, 593 U.S. ___ (2021) As of 2025, 28 states and the District of Columbia have banned juvenile life without parole outright.