Filed at 5:14 p.m. ET

WASHINGTON (AP) -- Thousands of small companies could avoid a law requiring special accommodations for disabled workers under a ruling Tuesday by the Supreme Court.

Congress exempted businesses with fewer than 15 employees from the landmark 1990 Americans with Disabilities Act. But lawmakers did not spell out who should be considered an employee.

In a 7-2 decision, the court ruled against a disabled woman who contended a small company's partners and shareholders should be counted as employees.

The decision mainly affects professional service companies like law firms, medical practices and accounting offices, though advocates for the disabled were split on the likely impact.

``It's unfortunate that the court has taken a miserly reading of this broad civil rights law,'' said Peter Blanck, a University of Iowa law professor specializing in the disabilities law. ``Companies will think twice about whether or not they have to make an ADA accommodation.''

But Max Lapertosa, a disability rights attorney in Chicago, said the guidelines laid out by the Supreme Court are specific and could make it harder for companies to claim some shareholders are not employees.

Companies that fall under ADA must make accommodations for disabled workers and cannot discriminate against someone based on a disability. The businesses can face lawsuits for violating the law.

Most small business owners would like to avoid the law because they want to focus on their jobs, not defending lawsuits and keeping up with paperwork, Washington labor attorney Lawrence Lorber said. He said the court's ruling will prompt businesses to rewrite contracts, tailored to the court's decision.

In this case, an Oregon medical clinic sued by a former employee argued it was too small to be subject to the ADA. The clinic, owned by a group of doctors, said the doctors were not employees. The other side wanted to count the doctors that way, which would have pushed the clinic over the 15-employee cutoff.

Though the disabilities law does not define who is an employee, Justice John Paul Stevens said the court was persuaded by the standards used by the Equal Employment Opportunity Commission. The EEOC says someone is not an employee if, for example, the person cannot be fired or is liable if a company loses money.

Stevens said the doctors at Clackamas Gastroenterology Associates appear to fall into that category because ``they apparently control the operation of their clinic, they share the profits and they are personally liable for malpractice claims.''

In a dissent, Justices Ruth Bader Ginsburg and Stephen Breyer said the court should not go out of its way to protect companies from having to follow the disabilities law. They also said the court's interpretation puts too much emphasis on a company ownership structure, not its size.

The Oregon clinic was sued by an employee who claimed she lost her job because of a disability, a debilitating tissue disorder. Justices sent the case back to a lower court for another look at the woman's claims.

In recent years, the court has repeatedly limited the scope of the ADA, which is best known for requiring wheelchair ramps at many public buildings. The Tuesday ruling also could affect company liability under other federal anti-discrimination laws.

The case is Clackamas Gastroenterology Associates v. Wells, 01-1435.