This article examines the possibility of devising membership criteria for the Non-NPT Nuclear Weapons States (NWS) (India, Pakistan and Israel) in the Nuclear Suppliers Group (NSG). The question whether membership should be granted to these nuclear outliers or not should be determined after considering the nuclear history, their overall approach towards the Nuclear Non-Proliferation Regime (NPR) of these states and the debate on the proposed applicability of uniform membership criteria. There is a possibility of mainstreaming these states because some are emerging nuclear energy markets and others have the potential to become future markets. Furthermore, they do have nuclear weapons, therefore, it is vital to incorporate them in the existing export controls regimes to inhibit horizontal proliferation by implementing stringent measures. This study investigates policy recommendations for the international community to incorporate the Non-NPT nuclear weapon countries in the NSG. The paper concludes that a positive upshot of such a step would be granting membership to the mentioned states and such an unbiased approach would diminish global nuclear proliferation concerns.