Endogenous money represents a mainstay of Post Keynesian (PK) macroeconomics. Analytically, it provides a critical linkage between the financial and real sectors, with the link running predominantly from credit to money to economic activity. The important feature is credit is placed at the beginning of this sequence, which contrasts with conventional representations that place money first. The origins of PK endogenous money lie in opposition to monetarism. Whereas neo-Keynesian economics challenged monetarism by focusing on the optimality of money supply versus interest rate targets, PK theory challenged monetarism’s description of the money supply process. PK theory is itself divided between “horizontalist” and “structuralist” approaches to the money supply. Horizontalists believe the behavior of financial institutions is unconstrained by the availability of liquidity (reserves) provided by the central bank and the supply-price of finance to banks is fixed at a price set by the central bank. Structuralists believe liquidity pressures matter and the supply price of finance to banks can increase endogenously. Horizontalists can be further sub-divided into “strong” and “weak” positions. The strong position holds the bank loan supply schedule is horizontal and interest rates are unaffected by lending. The weak position holds that interest rates may rise with lending if borrower quality deteriorates. The PK debate has been useful in articulating the mechanics of the money supply process, but inadequate attention has been paid to the implications of endogenous money for interest rate determination, the business cycle, and economic growth.