Excerpt: At prices often 80 percent cheaper than those of brand-name medicines, generics have become a key tool for health insurers and employers trying to hold back soaring medical costs. There's hardly a health plan today that doesn't use higher co-payments on branded drugs as a way to nudge employees toward less-expensive copycat versions. But as employees re-enroll in benefit plans this fall, many will encounter more-aggressive efforts to make generics the clear-cut choice.