The national teachers' unions are nervously eyeing a provision in a Senate version of the health-care overhaul now working its way through Congress that they say could ultimately squeeze medical benefits for educators. The language would tax insurance companies and plan administrators that offer what the measure defines as high-cost health coverage--often referred to as "Cadillac" or "gold-plated" plans--to help pay for the broader effort to expand access to health insurance while better controlling costs. But many officials in organized labor, including teacher representatives, argue that a tax imposed on companies would likely be passed along to workers in the form of higher premiums or less comprehensive benefits. That would be unfair, they say, to workers who have given up higher pay in exchange for strong health benefits--a good description of a lot of their members. If the Senate Finance Committee provision becomes law and leads to scaled-back health-care coverage for many employees, that could make it harder for school districts to attract and retain teachers, particularly in hard-to-staff subjects, union officials and policy analysts say. Supporters of the proposed tax say that if employers chose to scale back plans because of it, they might shift the money into salaries. But opponents argue that significantly higher salaries for public-sector employees, including teachers, are not likely in the foreseeable future, given the budget fallout from the recession. Still, some economists, in addition to suggesting that a reduction in benefits could bring a shift to salaries, see such a tax as part of a push to bring equity and fairness to health-care financing.