Prevention has never been the cornerstone of American medicine. In this country, we tend to go to the doctor only when something is wrong, a habit long bemoaned by researchers and medical groups. The federal government aims to change that, and soon. Starting this year, insurers will be required under the Affordable Care Act to completely cover such services as annual physicals, childhood vaccinations and dozens of screening tests for everything from high blood pressure to abdominal aortic aneurysms. Just last month, the Department of Health and Human Services released additional guidelines specifying fully covered preventive services for women. Mammograms, cervical cancer screening and other services already had been mandated; the new recommendations expand that list to include screenings for human papillomavirus and domestic abuse, and reimbursement and counseling for contraceptives. These services are to be fully covered by most insurance plans beginning in August 2012. Despite these new regulations, there's still a lot of ambiguity — and not just among consumers — about what qualifies as preventive care and what insurers are obligated to pay for.