Getting a library card, going to the dentist, and keeping a job will soon yield up to $6,000 a year in bonus cash under a test program that New York City is trying as part of Mayor Bloomberg’s anti-poverty initiative.

About 13,000 families will be eligible for the payments, part of a $50 million program whose details were announced yesterday by the deputy mayor for health and human services, Linda Gibbs.

The idea is to offer payments to encourage behaviors that have been shown to reduce poverty. A library card for an elementary or middle school student will bring his parents $50; a preventive dental visit brings $100 for each family member; and a steady full-time job pays $150 extra a month.

Conditional cash transfers have become a popular anti-poverty experiment in the developing world, but New York City’s will be the first American attempt.

The vice president of the Center for Global Development, Ruth Levine, praised Mr. Bloomberg for taking that step. “It’s exciting to see that the mayor has decided to look at the evidence,” she said, calling similar projects some of the world’s most research-proven social programs.

Much of the money is tied to educational goals, such as attending a parent-teacher conference ($25 per conference, maximum two conferences a year), downloading your child’s test results ($25 per download, maximum five downloads a year), and getting a child to attend school 95% of the time ($25 a month for parents, and an extra $25 for high schoolers).

One prong of the experiment — actually three separate projects that will have three sets of participants — will pay fourth- and seventh-graders incremental gifts based on how well they do on math and reading tests. Another prong, which targets low-income families and is the only to promise a maximum $6,000 in rewards, will pay high school students for things like taking a college entrance exam, the PSAT ($50), and graduating ($400).

Ms. Gibbs said the focus has to do with education’s proven track record. “You cut your poverty rate in half if you can get that college degree,” she said.

Funded by private donations, the Opportunity NYC program is now set to last just two years. But Ms. Gibbs made it clear that Mr. Bloomberg has broader ambitions. “At this point in two years we’ll be looking to see if there is enough promise in this approach that we would be willing to commit city money to it,” she said.

The Rockefeller Foundation, George Soros’s Open Society Institute, and Mayor Bloomberg are among the private financiers.

Whether an expanded project could garner political support is unclear.

A policy analyst at the New America Foundation, Rourke O’Brien, said the proposal’s unique blend of direct cash transfers and a commitment to personal responsibility could be broadly appealing, but some policy experts were skeptical.

A fellow at the right-leaning Manhattan Institute, Heather Mac Donald, scoffed at what she described as another extension of the welfare state. “When does this program ever stop?” she asked. “When do you stop paying people?”

Meanwhile, a senior economist at the left-leaning Fiscal Policy Institute, Trudi Renwick, questioned whether $6,000 would be enough to make a difference to a family. “If people are struggling to survive,” she said, “they can’t go to parent-teacher meetings.”

Half the program’s participants will be a control group, receiving no cash incentives — a design that will aid researchers charged with determining the program’s effects.

Their research will be ongoing, as the mayor’s staff hopes to build a case for expanding parts of the program, should they work.

No participants have yet been chosen. Ms. Gibbs said recruitment will begin this summer.