Congress created the nation’s only federally funded school voucher program in the District to give the city’s poorest children a chance at a better education than their neighborhood schools offer.

But a Washington Post review found that hundreds of students use their voucher dollars to attend schools that are unaccredited or are in unconventional settings, such as a family-run K-12 school operating out of a storefront, a Nation of Islam school based in a converted Deanwood residence, and a school built around the philosophy of a Bulgarian psychotherapist.

At a time when public schools face increasing demands for accountability and transparency, the 52 D.C. private schools that receive millions of federal voucher dollars are subject to few quality controls and offer widely disparate experiences, the Post found.

Some of these schools are heavily dependent on tax dollars, with more than 90 percent of their students paying with federal vouchers.

Yet the government has no say over curriculum, quality or management. And parents trying to select a school have little independent information, relying mostly on marketing from the schools.

The director of the nonprofit organization that manages the D.C. vouchers on behalf of the federal government calls quality control “a blind spot.”

“We’ve raised the question of quality oversight of the program as sort of a dead zone, a blind spot,” said Ed Davies, interim executive director of the D.C. Children and Youth Investment Trust Corp. “Currently, we don’t have that authority. It doesn’t exist.”

Republicans in Congress established the D.C. voucher program eight years ago to demonstrate the school-choice concepts that the party has been espousing since the 1950s. Vouchers were once thought to be moribund, but came roaring to life in 2010 in states where Republicans took control. Fourteen states have created voucher programs or expanded existing ones in recent years.

Some states, such as Wisconsin, now include middle-class families in their voucher programs. Other states, including Virginia, have begun indirectly steering public dollars to private schools by offering tax credits to those who donate to scholarship funds.

In some cases, the public has pushed back against the idea of routing state dollars from public to private schools. Legal challenges are pending in Colorado and Indiana. In the November elections, Florida voters rejected a ballot amendment that would have permitted tax dollars to flow to religious institutions, including parochial schools. That would have enabled the state to revive a voucher program that had been declared unconstitutional in 2006 by its highest court. Yet Florida continues to offer vouchers for disabled students who want to attend private schools and awards tax credits to corporations that donate to private-school scholarship programs.

In the District, it’s clear that vouchers have provided many children with an education at well-established private schools that otherwise would have been out of reach, and their parents rave about the opportunity. Of the 1,584 District students now receiving vouchers, more than half attend Catholic schools and a handful are enrolled at prestigious independent schools such as Sidwell Friends, where President Obama sends his daughters.

But the most comprehensive study of the D.C. program found “no conclusive evidence” that the vouchers improved math and reading test scores for those students who left their public schools.

The study, released by the U.S. Department of Education in 2010, found that voucher students were more likely to graduate than peers without vouchers, based on data collected from families. And parents reported that their children were safer attending the private schools, though the students themselves perceived no difference.

Congress set aside $20 million for the D.C. voucher program this year. Since 2004, the federal government has appropriated $133 million for the program.

Private schools that participate in the D.C. program don’t have to disclose the number of voucher students they enroll or how much public money they receive, and many declined to release such information to The Post.

While public schools must report test scores and take action when they don’t meet goals, private schools participating in the D.C. voucher program are insulated from such interference.

The schools must administer a single standardized test, but can choose the type. Those scores are not made public, and schools can stay in the voucher program no matter how their students fare.

Schools that accept vouchers are required to hold a certificate of occupancy and employ teachers who are college graduates, but they do not have to be accredited. The Post found that at least eight of the 52 schools are not accredited.

Parents, not the government, should determine a school’s quality, according to Kevin Smith, a spokesman for House Speaker John A. Boehner (R-Ohio), a proud product of Catholic schools who designed the voucher program. “Our belief is that parents — when provided appropriate information — will select the best learning environment for their children,” he wrote in an e-mail.

At Archbishop Carroll High School, where 40 percent of students receive vouchers, principal Mary Elizabeth Blaufuss agrees. “The question is, to what extent do we trust parents to make educational decisions for their kids?” she said.

Santa Carballo knew little about the Academia de la Recta Porta before enrolling her daughter, Emma, through the voucher program. She chose it because it was across the street from the Catholic school for boys that her son attends, also with a voucher, and it seemed better than a neighborhood public school that has failed for years to meet achievement targets.

“This is private, it’s good,” said Carballo, an immigrant from El Salvador who works as a waitress and struggles with English. “It’s more intelligent. And it’s religious, it’s good. I’m so happy.”

A nondenominational Christian school, the Academia charges $7,100 a year and occupies a soot-stained storefront between a halal meat shop and an evening wear boutique on a busy stretch of Georgia Avenue NW near the Maryland line.

The K-12 school consists of two classrooms. A drum set and keyboard are stowed in a corner for music class; for gym, students travel nearly two miles down Georgia Avenue to the city’s Emery Recreation Center.

Annette and Reginald Miles founded the unaccredited school 13 years ago. He is the pastor of the associated church, she is the school director, their daughter is a teacher and their grandson is a student.

Annette Miles declined to say how many of her 70 students receive vouchers. If the program were to end, the Academia would “have to stretch with fundraising” to continue operating, she said.

To be eligible for a voucher, families must qualify for food stamps or meet other income requirements.

Through the D.C. program, the federal government pays about $8,000 a year for each elementary school student and $12,000 for high schoolers. That’s less than the $18,000 a year it costs to educate one child in the D.C. Public Schools. Many of the participating private schools do not offer costly services for children with disabilities, who make up about 18 percent of the DCPS school population.

The voucher payments are enough to cover tuition at most Catholic schools, which enroll about 52 percent of D.C. voucher students. But they pay only a fraction of costs at elite institutions such as the Sheridan School in Northwest D.C., where charges can reach about $30,000 a year.

Tiblez Berhane has a daughter in eighth grade who is attending Sheridan with a voucher and financial aid from the school. “It’s wonderful,” said Berhane, an immigrant from Eritrea who works in a day-care center. “We could never afford this.”

While Sheridan, Sidwell Friends and the Washington International School each have one voucher student, the Academy for Ideal Education depends almost entirely on the federal program.

Founder Paulette Jones-Imaan created the school more than two decades ago, aiming to provide a nurturing environment with small classes and a learning model known as “Suggestopedia,” a philosophy of learning developed by Bulgarian psychotherapist Georgi Lozanov that stresses learning through music, stretching and meditation. Jones-Imaan melds that philosophy with an African-flavored approach that includes students addressing teachers as “Mama” and “Baba,” honorifics meaning mother and father.

Jones-Imaan also founded a K-12 public charter school, Ideal Academy, based on the same educational philosophy, in 1999. She served on the board for more than a decade.

But the charter school ran into trouble. Last year, the D.C. Public Charter School Board threatened to close it because of chronic poor performance. Ideal Academy agreed to shutter its high school, which had a particularly poor record, in order to keep its lower grades open. The preschool-8th grade Ideal Academy was classified as “inadequate” this year by the city’s charter officials, which means it could be closed if it doesn’t improve.

Meanwhile, the private Academy for Ideal Education continues on. More than 90 percent of its approximately 60 students are paying the $11,400 tuition with vouchers, Jones-Imaan said. “If this program were to end, this school would end,” she said.

While some schools have libraries, art studios and athletic fields, the Muhammad University of Islam occupies the second floor of a former residence east of the Anacostia River. The unaccredited K-8 school is supported by the Nation of Islam, according to director Stephanie Muhammad.

Parents choose the school because of its small classes, safety and strict discipline, she said.

About one-third of the 55 students hold vouchers. Few of the others can afford the $5,335 annual tuition, Muhammad said. They are asked to help defray tuition by raising funds. Last month, they sold pizzas. This month, it’s coffee and tea.

The classrooms are small, located in what were perhaps once bedrooms. On the walls are posters of Louis Farrakhan, the controversial leader of the Nation of Islam.

On a recent visit, the only bathroom in the school had a floor blackened with dirt and a sink coated in grime. The bathtub was filled with paint cans and cleaning supplies concealed by a curtain.

Muhammad said in a subsequent interview that the bathroom is used only in emergencies, and students typically use a restroom on the floor below in a day-care center that she had previously described as unrelated to the school.

Kevin P. Chavous, a former D.C. Council member and now a senior adviser to American Federation for Children, which lobbies for voucher programs nationwide, said schools receiving public funds should meet quality standards. But supporters of the D.C. program have been focused on overcoming political challenges, he said.

“There should be some accountability measures in all these programs,” Chavous said. “Our biggest challenge has been the constant threats to shut this down before we can even measure the schools.”

Since Congress created the voucher program in 2004, Boehner and Sen. Joseph I. Lieberman (I-Conn.) have regularly wrestled with Democrats over its fate. Republicans and Lieberman want to expand the program; Democrats want to phase it out.

“Our goal is to provide a quality education to all children — not just a few — which is why the Obama administration does not believe vouchers are the answer to America’s educational challenges,” said Justin Hamilton, a spokesman for Education Secretary Arne Duncan.

Del. Eleanor Holmes Norton (D) and D.C. Mayor Vincent C. Gray (D) also are opposed to the voucher program, saying public dollars should go toward improving public schools where they can help the most students.

Still, the program has offered some children a crucial path out of troubled city schools.

Ophelia Johnson and her daughters were homeless when she learned about the voucher program. She obtained vouchers for both her daughters and enrolled them at the Calvary Christian Academy, which she credits with providing her children a secure, caring and consistent environment as she pulled her life together.

“It’s wonderful,” Johnson said about the voucher program that allowed her daughters to attend the academy. “The atmosphere, the education, and it’s also a Christian school. They taught my girls.”

Now, Johnson is employed, newly remarried and living with her daughters in a condominium on Capitol Hill. Her older daughter, Tabitha, is applying to colleges.

“She’ll be the first to go in the family,” Johnson said, pride in her voice.