On February 12, 2009, the Agriculture Committee of the US House of Representatives approved the Derivatives Markets Transparency and Accountability Act of 2009 (DMTA), a bill that would require, among other things, prospective over-the-counter (OTC) transactions in commodities excluded or exempt from the Commodities Exchange Act (CEA) to be settled and cleared through a designated clearing organization approved by the CFTC, or a clearing agency regulated by the SEC, or in some circumstances by a clearing agency with a foreign government regulator.  Other provisions of the bill would impose limits on the speculative positions in commodity derivatives, and authorize the CFTC and the President to suspend trading in “naked” credit default swaps when an SEC suspension order is in effect.  In short, the bill proposes a dramatic revision of the mechanics by which over-the-counter derivatives markets in the US (and to some extent, outside of the US) have operated since the 2000 amendments to the CEA.  If enacted in its current form, the bill would move the swaps market away from the bilateral, OTC model toward a model dominated by standardized contracts.  We provide a detailed analysis of how the bill would work and how it would change the regulatory landscape for OTC derivatives.