Abstract：
Over 70% of Medicaid beneficiaries are enrolled in Medicaid managed care (MMC). MMC provider networks therefore represent a critical determinant of access to the Medicaid program. Many MMC insurers also participate in commercial insurance markets where prices are high, and some insurers exercise considerable market power. In this paper, we examined the relationship between commercial insurer market power and MMC physician network breadth using linked national enrollment data and provider directory data. Insurers with more commercial market power had broader Medicaid physician networks. Insurers with over 30% market share had 37.3% broader Medicaid networks than insurers in the same county that had no commercial market share. These differences were driven by greater breadth among primary care providers, as well as other specialists including OB/GYNs, surgeons, neurologists, and cardiologists. Commercial insurance market power may have spillovers on access to care for MMC beneficiaries.
摘要：
超过70％的医疗补助受益人参加了医疗补助管理式护理（MMC）。因此，MMC提供商网络代表了访问Medicaid计划的关键决定因素。许多MMC保险公司还参与价格高的商业保险市场，一些保险公司行使相当大的市场力量。在本文中,我们使用关联的全国注册数据和提供者目录数据,研究了商业保险公司市场力量与MMC医师网络广度之间的关系.拥有更多商业市场力量的保险公司拥有更广泛的医疗补助医生网络。市场份额超过30％的保险公司的医疗补助网络比没有商业市场份额的同一县的保险公司扩大了37.3％。这些差异是由初级保健提供者之间更大的广度驱动的，以及其他专家，包括妇产科医生，外科医生,神经学家,和心脏病学家。商业保险市场力量可能会对MMC受益人获得护理产生溢出效应。
