The rules of international adoption are about to undergo significant changes that could affect everything from the countries where Americans can adopt to the fees they'll have to pay.

More than a decade after signing it, the U.S. is close to finally implementing a global treaty known as the Hague Convention on Intercountry Adoption, designed to curb abuses such as child trafficking that have long marred international adoptions. The State Department issued most of the final regulations earlier this year, and last month it opened the application process for U.S. adoption providers (such as agencies and attorneys) to become accredited to work on adoptions of children from the 69 Hague countries around the world.

If all goes as planned, the U.S. will ratify the Hague Convention sometime next year, though no one knows yet exactly what the new policy will mean for prospective parents. One benefit: The rules require agencies to try harder to collect health information on children.

Yet some adoption professionals say adopting a baby overseas may take longer or cost more money than it already does. The roster of countries that Americans adopt a lot of babies from could change as well, and that has some people with pending applications worried they will be caught in limbo.

"People are nervous," says Diane B. Kunz, executive director of the New York-based Center for Adoption Policy, a nonprofit group that works to educate people about domestic and international adoption. "People are saying to themselves, 'How will this affect me?'"

Some countries that are party to the treaty but that send relatively few children to the U.S. for adoption -- such as Brazil and Mexico -- might allow more American adoptions once the U.S. implements the new guidelines, experts say. Yet at least one very popular country of origin for U.S. adoptions, Guatemala, could be closed off, due to concerns over its compliance with the new rules.

Once the U.S. ratifies the Hague treaty, the convention's regulations will govern all adoptions in countries that are party to it. It will be against the law for Americans to adopt children from countries that have ratified the treaty but are in violation of its laws, such as Guatemala. Yet Americans will still be able to adopt children from nonconvention countries; Hague rules and safeguards won't technically apply to those adoptions.

The Hague Convention is widely regarded as an important step in making international adoption safer for the child, as well as the biological and adoptive parents. Countries that are party to the treaty have to follow specific procedures and guidelines, such as setting up a central authority to monitor international adoptions. They will also have to accredit agencies or individuals that arrange adoptions of children from Hague countries.

To date, 69 countries on six continents are parties to the convention. Despite signing the treaty in 1993, the U.S. has been slow to implement its rules, in large part because of debate among adoption advocates and politicians over everything from the costs of putting the new guidelines into place to whether gays and singles should be allowed to adopt. In 2000, Congress passed the Intercountry Adoption Act, which was meant to implement the new standards. Since then, the State Department -- chosen to be the central authority on adoption for the U.S. -- has issued drafts of the regulations and responded to more than 1,500 public comments.

All the while, international adoptions by Americans have been escalating -- with even stars such as Madonna traveling abroad to adopt. In fiscal year 2005, Americans adopted about 22,700 children from other countries, up from about 17,700 in 2000 and 8,900 in 1995. The vast majority of those children come from four countries: China, Russia, Guatemala and South Korea, not all of which are parties to the treaty. (China has ratified it; Russia is expected to ratify it sometime after the U.S. does; Guatemala has ratified it but isn't in compliance with its rules; and South Korea isn't a party to it.)

Many experts believe that the Hague Convention will benefit adoptive parents by making foreign adoptions more predictable and transparent. Once the rules are implemented, U.S. adoption agencies or individuals, such as adoption lawyers, approved to work in a Hague country will go through an accrediting process, as well as the state licensing that is required now. In addition, the agency will have to carry a minimum of $1 million in liability insurance, and in many cases will be held responsible for staff working in other countries.

"This will make it more difficult for shady operators to work in adoption both in countries of origin and in the U.S.," says Thomas Atwood, president of the National Council for Adoption, or NCFA, a nonprofit research, education and advocacy organization based in Alexandria, Va.

No one knows exactly how many adoption providers there are in the U.S, but experts estimate there are about 400, with as many as half expected to apply for accreditation. The State Department has charged two entities with accrediting U.S. agencies and individuals to arrange for adoptions from Hague countries: the Council on Accreditation, a New York-based nonprofit, and the Colorado Department of Human Services. There also will be a formal process for complaints against an agency.

One important Hague rule specifies that agencies will have to disclose the full cost of an adoption upfront. Currently, foreign officials sometimes demand fees before handing over a child. "There have been costs that weren't recorded," says Fred Greenman, legal adviser to the American Adoption Congress. "People were instructed to take $5,000 to $10,000 in cash."

Another benefit for prospective parents: They should have access to more information about the child they are adopting. Under Hague regulations, agencies will have to try harder to get credible health information on the child -- and to supply it to the adoptive parents. They will also be required to try to gather more information on the biological parents and share it with the adoptive parents, subject to local privacy laws. As part of the anti-trafficking protections, they will also have to ensure appropriate documentation is available before the child is adopted.

Additionally, some countries may open their orphanages up for more U.S. adoptions. Nations such as Mexico, India, the Philippines and Bolivia -- which have all ratified the treaty -- have indicated they could allow more U.S. adoptions of their children once the Hague treaty is ratified, according to Mr. Atwood of the National Council for Adoption. Other countries have essentially shut the door to U.S. adoptions, but may also liberalize their policies.

But some critics say the benefits to prospective parents may come at a cost. Currently, the total price of an international adoption -- including travel to the child's country -- typically range from about $15,000 to $30,000. To become accredited under the Hague regulations, adoption agencies will have to pay an additional fee of about $7,000 to $13,000 every four years, and will also need to pay staff to compile documentation for the accreditation process and to make sure they are compliant with Hague regulations. "Who is ultimately going to pay that? The adoptive parents," says Joan Hollinger, a professor at the University of California Berkeley's law school and a specialist on adoption law.

There are other potential problems. While the U.S. should remain open to adoptions from most countries that are parties to the treaty, it may cut off adoptions from Guatemala, the third-largest source of U.S. foreign adoptions, supplying 3,783 last year. The country has ratified the Hague convention, but hasn't set up a centralized authority to oversee adoption. In addition, there are concerns about trafficking of babies and coercion of birth mothers.

The situation is causing anxiety for some prospective adoptive parents, who wonder whether they stand to lose the approximately $25,000 cost of a Guatemalan adoption if the county is cut off while they are in the middle of the process. "There should be a lot of concern," says Tom DiFilipo, chief executive and president of the Joint Council on International Children's Services, or JCICS, a nonprofit advocacy organization for children's rights. Mr. DiFilipo says Americans who have submitted their preliminary paperwork to U.S. Citizenship and Immigration Services before any cutoff with Guatemala becomes official will be allowed to complete their adoption.

Even so, some adoption agencies, such as Spence-Chapin Services to Families and Children in New York, are advising people interested in adopting from Guatemala that they should also have a backup country in mind. "We just don't know what will happen," says Kathy Legg, the agency's executive director.

Many prospective parents also worry that the adoption agency they are working with won't get accredited, thereby holding up their adoption process. "If you're in the middle of an adoption and your agency fails to get accredited, your case would be transferred to another agency," says Richard Klarberg, chief executive and president of the Council on Accreditation.

Experts advise people interested in adopting a child from a Hague Convention country to ask the agency they are working with whether or not it is applying to become accredited. "You want an agency you know will continue to work in that country," says JCICS's Mr. DiFilipo.

Looking Abroad

Where to get information on international adoptions:

The State Department (www. travel.state.gov), the central U.S. authority on adoptions under the Hague treaty.

The National Council for Adoption (www. adoptioncouncil.org), a nonprofit research, education and advocacy group.

The Joint Council on International Children's Services (www.jcics.org), a nonprofit membership association of adoption agencies and child-advocacy groups.