More than 5.6 million Americans are in prison or have served time there, according to a new report by the Justice Department released Sunday. That's 1 in 37 adults living in the United States, the highest incarceration level in the world.

It's the first time the US government has released estimates of the extent of imprisonment, and the report's statistics have broad implications for everything from state fiscal crises to how other nations view the American experience.

If current trends continue, it means that a black male in the United States would have about a 1 in 3 chance of going to prison during his lifetime. For a Hispanic male, it's 1 in 6; for a white male, 1 in 17.

The numbers come after many years of get-tough policies - and years when violent-crime rates have generally fallen. But to some observers, they point to broader failures in US society, particularly in regard to racial minorities and others who are economically disadvantaged.

"These new numbers are shocking enough, but what we don't see are the ripple effects of what they mean: For the generation of black children today, there's almost an inevitable aspect of going to prison," says Marc Mauer, assistant director of The Sentencing Project, a nonprofit advocacy group based in Washington. "We have the wealthiest society in human history, and we maintain the highest level of imprisonment. It's striking what that says about our approach to social problems and inequality."

Numbering in the millions

Justice Department analysts say that experts in criminal justice have long known of the stark disparities in prison experience, but they have never been as fully documented. By the end of year 2001, some 1,319,000 adults were confined in state or federal prisons. An estimated 4,299,000 former prisoners are still alive, the new report concludes.

"What we are seeing is a substantial involvement of the public in the criminal-justice system. It raises a lot of questions in the national dialogue on everything from voting and sentencing to priorities related to state's expenditures," says Allen Beck, chief of correction statistics at the Bureau of Justice Statistics, who directed the report.

Nor does the impact of incarceration end with the sentence. Former inmates can be excluded from receiving public assistance, living in public housing, or receiving financial aid for college. Ex-felons are prohibited from voting in many states. And with the increased use of background checks - especially since 9/11 - they may be permanently locked out of jobs in many professions, including education, child care, driving a bus, or working in a nursing home.

Enfranchisement for ex-felons

More than 4 million prisoners or former prisoners are denied a right to vote; in 12 states, that ban is for life.

"That's why racial profiling has become such a priority issue for African-Americans, because it is the gateway to just such a statistic," says Yvonne Scruggs- Leftwich, chief operating officer of the Black Leadership Forum, in Washington. "It means that large numbers in the African-American community are disenfranchised, sometimes permanently."

Some states are already scaling back prohibitions or limits on voting affecting former inmates, including Maryland, Delaware, New Mexico, and Texas.

In addition, critics say that efforts to purge voting rolls of former felons could lead to abuses, and effectively disenfranchise many minority voters.

"On the day of the 2000 [presidential] election, there were an estimated 600,000 former felons who had completed their sentence yet because of Florida's restrictive laws were unable to vote," says Mr. Mauer of the Sentencing Project.

The new report also informs - but does not settle - one of the toughest debates in American politics: whether high rates of imprisonment are related to a drop in crime rates over the past decade.

The prison population has quadrupled since 1980. Much of that surge is the result of public policy, such as the war on drugs and mandatory minimum sentencing. Nearly 1 in 4 of the inmates in federal and state prisons are there because of drug-related offenses, most of them nonviolent.

Narcotic-related arrests

New drug policies have especially affected incarceration rates for women, which have increased at nearly double the rate for men since 1980. Nearly 1 in 3 women in prison today are serving sentences for drug-related crimes.

"A lot of people think that the reason crime rates have been dropping over the past several years is, in part, because we're incarcerating the people most likely to commit crimes," says Stephan Thernstrom, a historian at Harvard University.

Others say the drop has more to do with factors such as a generally healthy economy in the 1990s, more opportunity for urban youth, or better community policing.

But no one disagrees that prison experience will be a part of the lives of more and more Americans. By 2010, the number of American residents in prison or with prison experience is expected to jump to 7.7 million, or 3.4 percent of all adults, according to the new report.