As part of rejuvenated efforts at pursuing sustainable health care financing options that promote universal coverage, Ghana has adopted a National Health Insurance Scheme (NHIS) to provide financial access and universal coverage for health care, which is key in promotive, preventive, curative and rehabilitative health interventions for all at an affordable cost. However, since its operationalization in 2004, the policy is facing a lot implementation challenges that are threatening its viability. Our research investigates the financial sustainability of the scheme. This qualitative study was conducted between July, 2013 and July, 2014. Ten in-depth interviews were conducted with officials connected with the NHIS selected across the Ashanti and the three Northern regions of Ghana. Additionally, ten focus group discussions were also conducted and this was complemented by analysis of policy documents. The study reveals that the sustainability of the scheme is threatened by lack of funds which has resulted in indebtedness to service providers. Out-of-pocket payment has been re-introduced by service providers and in some cases, NHIS card holders who are unable to make upfront payment are rejected at health facilities. The study posits that the trend is likely to continue and perhaps even escalate unless a well planned policy intervention to refit the scheme is adopted and competently implemented.