Among the many provisions in the Affordable Care Act is a temporary, five-year, 10 percent increase in what Medicare pays for services provided by primary care clinicians—not only family practice doctors, general internists, and pediatricians, but also nurse practitioners, clinical nurse specialists, and physician assistants. Congress intended the change, along with others in the law, to reorient health care delivery toward primary care, which, if provided in a timely manner, can help reduce patients' need for more intensive, costly care later on. In a new issue brief, researchers at the Center for Studying Health System Change (HSC) and Mathematica Policy Research report what would likely happen if this increase in Medicare primary care fees were made permanent.