The effect of nurse practitioner scope of practice laws on primary care delivery

Nurse practitioners (NPs) are an increasingly integral part of the primary care workforce. NPs' authority to practice without physician oversight is regulated by state-level scope of practice (SOP) restrictions. To the extent that SOP restrictions prevent NPs from practicing to their full abilities and capacity, they could create inefficiencies and restrict access to health care. In this paper, I study what happens at primary care practices when states relax their SOP laws. Using a novel dataset of claims and electronic health records paired with a difference-in-differences research design, I quantify the effects of relaxing SOP laws on: (1) NPs' autonomy in their day-to-day jobs; (2) total workload and patient allocation between NPs and physicians; and (3) the provision of low-value services at primary care practices. I find some evidence that NPs practice more autonomously following SOP changes, but I find no evidence that relaxing SOP laws changes the volume nor allocation of patients to NPs, nor the provision of low-value services. Given the lower reimbursement that NPs typically receive, these findings suggest that allowing NPs to practice without physician oversight could reduce health care spending, without harming patients.