Money is critical for a regenerative future. Transforming it is an unavoidable social, political, and economic endeavor that must be a global priority if we are to prevent future financial crises, reduce economic inequality and adhere to our climate agreements and sustainability goals. For this transition to occur, we urgently need new economic and monetary paradigms that address the root causes of our current unsustainability, offer a new monetary ontology and design, and, more importantly, steer our monetary regime towards the regeneration of our social, economic and ecological landscapes. We need an Ecological Monetary Theory grounded in Ecological Economics and an Ecological Value Theory that lays down the foundations for the conscious democratization, decentralization, and diversification of money. In this work, we revisit and update the missing link between money and sustainability by proposing new ontological avenues and reviewing the design elements and degenerative processes built into the existing system. We also contribute to the development and emergence of an Ecological Monetary Theory by systematizing the ongoing monetary transition toward sustainability and by offering a set of principles drawn from the regenerative economics literature for the conscious design of monetary ecosystems that contribute positively to solving our societal challenges of the 21st century.