With 5 billion dollars in new federal funding to improve access to mental health services set to roll out over the next 10 years, a window of opportunity has opened to begin to close the long-standing gap in mental health funding in Canada. Public spending on mental health in Canada is only 7% of public spending on health overall (Jacobs et al., 2010), well short of the 9% called for in the Changing Directions, Changing Lives: The Mental Health Strategy for Canada (MHCC, 2012). This percentage is also well short of the disease burden comprised by mental illnesses, which ranges from 13% globally (WHO, 2011) to 23% in the UK (OECD, 2014). By comparison, recent figures from the Organisation for Economic Cooperation and Development (OECD, 2014) indicate that some countries devote as much as 18% of their health spending to mental health, with the UK sitting at 13%. Even with new targeted federal funding, closing, or at least narrowing, this gap will require careful attention to lessons learned in the past. This article explores how the gap in mental health funding came about in Canada and provides a more detailed analysis of the size of the gap itself. While it is now clear that the federal government will introduce a transfer that is directly targeted to mental health, there are still many policy options to consider for moving forward with next steps, including provincial/territorial contributions, accountability mechanisms, outcome measures, the insurance/financing model, and how tightly eligible expenses are tied to specific initiatives, population groups, or levels of evidence.