Features : : A Matter of Time: The Causes and Consequences of Rising Time Served in America’s Prisons
Trends | The Hidden Story of Rising Time Served
People are spending more time in prison, and the longest prison terms are getting longer.
To better understand long prison terms, we took a new approach to measuring how much time people spend in US prisons. We looked at annual snapshots of prison populations to see how long people had been in prison so far and compared those snapshots over time. This allowed us to include time served by people who are usually overlooked by more traditional methods.
Any amount of time spent in prison can feel long, but some terms are truly extreme. Because state policies greatly influence sentencing and release, we looked at the top 10 percent of people serving the longest prison terms in each state. We also tracked changes among people serving terms of 10 years or more. By either measure, the longest prison terms have been growing in both length and number.
On average, people are spending more time in prison.

These graphs represent a year-end snapshot of the average number of years that people in state prisons have been incarcerated so far. Many will go on to serve considerably more time.

Each state’s story is unique, but we found a consistent upward trend in the amount of time people spend in state prisons. Since 2000, the average time served has risen in all 44 states (including the District of Columbia) that reported complete data to the National Corrections Reporting Program.

In some states, this rise began years earlier. But these recent trends suggest that most states are still feeling the effects of policy decisions from the 1980s and ’90s that were designed to keep people in prison longer.

The increase has been sharpest among people convicted of violent offenses.

In most states, this trend is mostly—if not entirely—driven by an increase in time served for violent crimes. These changes have an outsized effect on the prison population, because people convicted of violent offenses make up more than half the people in state prisons and the majority of people with long prison terms.

Reforms tend to focus on low-level crimes. And though some have helped reduce prison time for minor offenses, the narrow focus of these reforms has intentionally excluded those who stay in prison the longest.

The longest prison terms are getting longer.

We looked at the 10 percent of the prison population in each state serving the longest terms, a measure that reflects each state’s unique population and policy environment. In most states, the average time served by the top 10 percent rose much more sharply relative to the rest of the prison population.

The average time served by this group, according to the most recent state data available, ranged widely from 9.5 years in South Dakota to 26.1 years in Massachusetts. In most states, the top 10 percent have spent an average of 15–25 years in prison so far.

For many states, this represents a staggering increase. In Michigan, for example, the average time served among the top 10 percent was 10 years in 1989. In 2013, the top 10 percent had served 26 years—a 160 percent increase. California saw its average among this group rise from 9.7 years to 24.9 between 1992 and 2014. In nearly half the states we looked at, the average time served by this group has risen by more than 5 years since 2000.

These steep increases over time and the variation across states points to the power of state-specific policy decisions.

A growing share of the prison population has served at least 10 years.

In 35 states, at least 1 in 10 people in prison have been there for a decade or more, according to the most recent data available. In California and Michigan, nearly 1 in 4 people have served at least 10 years.

In some states, this group may be growing mainly because fewer people are serving short terms. This trend is to be expected in states that have cut admissions and/or prison time for low-level offenses. For example, California’s Public Safety Realignment Act of 2011 sentenced thousands of people convicted of lesser offenses to county jails and probation, radically shifting the makeup of its prisons toward people with more serious convictions.

Meanwhile, the number of people who have served at least 10 years is also growing.

The shifting makeup of state prison populations doesn’t tell the entire story, as the absolute number of people serving 10 years or more has also increased. In at least 11 states, this number has more than doubled since 2000.

Tens of thousands of people nationwide are serving these long sentences, and many will stay much longer.

We can’t tackle mass incarceration without addressing long prison terms.

These trends have consequences. As more people spend more time in prison, states spend millions housing an aging prison population despite evidence that many of these people could be safely released. People serving long prison terms leave families behind, a cost that communities of color disproportionately bear. Many who finally return after a lifetime in prison find they are wholly unprepared to live in a world so different from the one they knew.

These trends aren’t accidental. Most can be traced back to specific policy decisions made decades ago that still influence our criminal justice system. That these trends vary so much across states suggests that the growth in time served is driven by state-level decisionmaking. States grappling with expanding prison populations will see their efforts to curb mass incarceration fall short unless reforms include those serving the longest prison terms.