Efforts are being made to crack down on "degree mills" that flood the US with fake degrees.
The Council for Higher Education Accreditation (CHEA) has written to the governors and attorneys-general of all 50 states to call attention to the problem and to ask them to look out for "accreditation mills" set up to give bogus universities a false cloak of respectability.
Judith Eaton, president of the CHEA, told the officials: "Rogue providers of higher education undermine the value of legitimate colleges and universities in your state as well as others.
"Degree mills reduce the value of degrees that are awarded, and their fraudulent credentials threaten public safety, especially when fake degrees are offered in such vital areas as health and engineering."
Although some states already have legislation to combat bogus degrees, the CHEA has called for greater action country-wide.
It asks governors to establish or strengthen definitions in law for "degree mill" and "accreditation mill", to take additional legislative and regulatory steps to discourage or eliminate the use of fraudulent credentials, and to raise public awareness of the problem.
Ms Eaton, who is based in Washington DC, said: "The recent Higher Education Opportunity Act of 2008 contains the first federal definition of degree mills and requires ongoing action from the Department of Education to educate the public about this problem.
"While we understand that the various states address such issues independently from the federal Government, the new federal definition may be useful to consider when developing future state initiatives."
A CHEA-compiled database currently lists 7,000 legitimate degree-granting and non-degree-granting institutions, more than 17,500 accredited programmes and 80 recognised accreditors.