National Health Insurance Scheme (NHIS) aims at ensuring that every Nigerian has access to affordable and qualitative healthcare services, hence the commencement of Formal Sector Social Health Insurance Programme Implementation for Federal Government Civil Servants in 2005. The objective of this study is to examine the challenges of access to affordable and qualitative services among the Federal Workers in Kano State. The study employed mixed survey design in administration of questionnaires to the registered NHIS enrolees and conducted interviews for the Desk Officers in Healthcare facilities; HMOs’ Quality Assurance Managers and NHIS Heads of medical departments. Three theories were reviewed, and the research adopted institutional theory because NHIS as a public institution is responsible for the implementation of health insurance policy in Nigeria. Findings from the study showed that, the NHIS pool of funds (contributions) had significantly reduced Out of Pocket Expenses (OPE) and enhanced affordability. Also participation of private facilities enhanced provision of qualitative healthcare services among Federal workers in Kano State. On the challenges of access to affordable and qualitative health care services, the study observed that programme implementation involved multi-level stake holder engagements, while the identifiable challenges include lack of proper referrals; irregular quality assurance visits, delay in payment of fee-for-service claims and low level of awareness. The study recommended that risk sharing through PPP arrangements in the implementation of the NHIS programmes not only in the formal sector will address the challenges and ensure achievement of Universal Coverage in Nigeria. Keywords: National Health Insurance Scheme, Healthcare Services, Qualitative, Affordable Services.