In 2014, the Affordable Care Act will create an estimated 16 million newly insured people. Coupled with an estimated shortage of over 60,000 primary care physicians, the country's public health care system will be at a challenging crossroads, as there will be more patients waiting to see fewer doctors. Nurse practitioners (NPs) can help to ease this crisis. NPs are health care professionals with the capability to provide important and critical access to primary care, particularly for vulnerable populations. However, despite convincing data about the quality of care provided by NPs, many managed care organizations (MCOs) across the country do not credential NPs as primary care providers, limiting the ability of NPs to be reimbursed by private insurers. To assess current credentialing practices of health plans across the United States, a brief telephone survey was administered to 258 of the largest health maintenance organizations (HMOs) in the United States, operated by 98 different MCOs. Results indicated that 74% of these HMOs currently credential NPs as primary care providers. Although this represents progress over prior assessments, findings suggest that just over one fourth of major HMOs still do not recognize NPs as primary care providers. Given the documented shortage of primary care physicians in low-income communities in the United States, these credentialing policies continue to diminish the ability of NPs to deliver primary care to vulnerable populations. Furthermore, these policies could negatively impact access to care for thousands of newly insured Americans who will be seeking a primary care provider in 2014.