According to a recent Congressional Office of Technology Assessment survey,1 genetic testing by employers for the purposes of excluding individuals from particular jobs remains rare. This should not be surprising. As the current report2 of the Council on Ethical and Judicial Affairs of the American Medical Association points out, the potential of such tests as exclusionary screens will always be restricted by the limits that the uncertainties of genetic penetrance and expressivity impose on the tests’ predictive power. These confounding biological variables will be greatest precisely with the common, causally complicated, economically significant health problems that concern employers the most.3 Moreover, according to at least some of its congressional supporters, the recently enacted Americans With Disabilities Act is intended in part to prohibit employers from using exclusionary non-job-related genetic tests, including tests for genetic risk and gene carrier status.4 Any dramatic increase in workplace genetic screening