We present results of the first ever quantitative and qualitative evaluation of four diverse smartphone authentication schemes with older adults to uncover a host of usability issues unique to them. We show that older adults spend significantly more time to configure the authentication schemes and to authenticate; however, unlike their young counterparts, speed is not a concern to them. Older adults prefer easy to remember and non-dexterous authentication schemes. Consequently, their usability preferences in terms of annoyance and fatigue are significantly different from the preferences of young adults.