In the climax of a year-long dispute, a warning that legal action will be taken against universities which continue the practice has been inserted into proposed federal guidelines.
The guidelines are being pushed by civil rights bodies including the powerful US Commission on Civil Rights, a fact-finding agency which reports to the President and Congress on discrimination issues.
Critics say there is no evidence of such discrimination, and argue that the move is an attempt to give special help to low-performing minority students, rather than improve their schools. The entrance exams are generally taken by university-bound high school juniors and seniors, who are aged 16 or 17.
The proposal encourages the use of criteria including grades, portfolios and personal interviews in addition to the entrance test scores in admission decisions. It is based on the principle that if minorities do not score as well as whites on standardised tests, a college that relies on these tests exclusively in its admissions process has engaged in discrimination under US law.
"The use of any educational test which has a significant disparate impact on members of any particular race, national origin, or sex is discriminatory," the guidelines say.
Universities complain that other measures, such as grades, vary so much between schools that it is difficult to compare applicants from different regions.
The dispute is the latest in a series over the admissions tests. The University of California at Berkeley is facing a lawsuit for relying on exam scores in admission, brought by applicants who say the tests are biased against racial minorities and low-income students.
And while minorities complain that tests discriminate against them, exam scores also are the basis for lawsuits brought by white students against the universities of Michigan and Washington, which claim they were rejected in favour of minority applicants with lower scores by officials trying to ensure that their enrolment was diverse.
In an effort to sidestep the controversy, some states are trying to devise new formulas for university admission. In Georgia, for example, public universities now calculate a "freshman index" based almost equally on grades and test scores.
The final guidelines are due out in the autumn, and are likely to be challenged in the courts.
* The country's largest teachers' union, the National Education Association, is trying to shed its anti-reform image. It has publicly agreed that bad teachers should be fired - and experienced teachers should help to review the performance of their younger peers.
United States 958
United Kingdom 800
Average teaching hours per year for primary pupils (Source - OECD)