Private insurance plans are striving to bend the healthcare cost curve in response to the 2010 Affordable Care Act. There is growing concern that this trend may lead unexpectedly to inadequate or delayed coverage for plan members due to possible shrinkages of provider networks. Through a thorough review of the literature on provider network adequacy, this study identifies 34 potential criteria instrumental to measuring the adequacy of the networks and reports them one by one with their respective advantages and disadvantages. In addition, measurement strategies for each criterion are proposed. Among the 34 potential criteria, this study recommends 11 criteria best suited to measure network adequacy in Idaho. Specific data are reported for reference that could be useful to Idaho Department of Insurance in developing network adequacy standards.