A New York Times investigation found that at least 2,700 similarly dangerous incidents were also not factored into the rating system run by the federal Centers for Medicare and Medicaid Services, or C.M.S., which is designed to give people reliable information to evaluate the safety and quality of thousands of nursing homes.

Many of the incidents were uncovered by state inspectors and verified by their supervisors, but quashed during a secretive appeals process, according to a review of thousands of pages of inspection reports and nursing home appeals, which The Times obtained via public-records requests. Others were omitted from the C.M.S. ratings website because of what regulators describe as a technical glitch.

The Times this year has documented a series of problems with Medicare’s ratings system. Much of the data that powers the system is wrong and often makes nursing homes seem cleaner and safer than they are. The rating system also obscures how many residents are receiving powerful antipsychotic drugs.

But the problems with the inspection process, which are the core of the ratings system, are the most consequential.

On-the-ground inspections are the most important factor in determining how many stars homes receive in Medicare’s rating system. The reports that inspectors produce give the public an unvarnished view inside facilities that house many of the country’s most vulnerable citizens.

On the rare occasions when inspectors issue severe citations, nursing homes can fight them through an appeals process that operates almost entirely in secret. If nursing homes don’t get the desired outcome via the informal review, they can appeal to a special federal court inside the executive branch. That process, too, is hidden from the public.

Read more in the New York Times.