The developers and owners of an estimated 100,000 city apartment units may set their sights on Washington to avoid paying tens of millions of dollars for violations of the federal Fair Housing Act.

The New York Times reported yesterday that the U.S. attorney in Manhattan, Michael Garcia, is opening an investigation into whether thousands of apartment units that satisfied city regulators failed to meet federal requirements for wheelchair accessibility.

At issue are provisions of the Fair Housing Act that include seven features that must be found in most new apartment buildings. One feature is that light switches be placed below a certain height. Another is that bathroom walls be reinforced to allow for the installation of grab bars.

The U.S. Department of Housing and Urban Development recognizes 10 different building codes or design manuals that satisfy the Fair Housing Act requirements.

The set of design requirements long required by New York City for wheelchair accessibility is not listed among those 10. Federal housing officials said yesterday that they are not aware of any attempt by New York City or local developers to get the city’s regulations incorporated into HUD’s list. Mr. Garcia’s investigation could spur an effort by developers and property managers to have that happen.

Violations of the Fair Housing Act can carry fines of up to $110,000 each. Courts can order that apartments be retrofitted for tenants who use wheelchairs. That a specific unit is currently occupied by a tenant who doesn’t require the modifications has no effect on whether prosecutors can seek penalties, federal housing officials said yesterday.

“Everybody got fair warning,” the assistant secretary for Fair Housing and Equal Opportunity, Kim Kendrick, said in an interview.

The Times article estimated that more than 100,000 units built since 1991, when the federal law went into effect, may require renovations.

Until Mr. Garcia’s investigation, which has already resulted in one suit against a developer, it is not apparent that any branch of the federal government found anything lacking with New York’s wheelchair-accessibility requirements, which are known as Local Law 58.

While HUD has charged landlords with refusing to rent to disabled tenants and denying a disabled tenant an accessible parking lot, the department doesn’t appear to have charged any landlords over a lack of wheelchair accessibility in an apartment unit within New York State in the last 18 months, according to a review of HUD press releases. HUD has a field office in Lower Manhattan.

New York officials are defending Local Law 58, which preceded the provisions in the federal law, as adequate at protecting the rights of disabled tenants as the federal law.

“Our Local Law 58 indeed addresses all features of accessibility required by” the federal Fair Housing Act, the city’s corporation counsel, Michael Cardozo, wrote in a letter to Mr. Garcia last month.

Mr. Cardozo’s letter quotes a remark Senator Schumer, then a congressman, gave during a debate on the proposed federal law. Mr. Schumer described Local Law 58 as more “stringent.”

Still, Mr. Schumer said, “I am convinced that the bill’s minimal requirements for accessibility are the way to go.”