EPA is approving a State Implementation Plan (SIP) revision submitted by the State of Maryland. The revision consists of amendments to Maryland's Nitrogen Oxides ( NO<INF>X</INF>) Budget Program. The revisions implement the Ozone Transport Commission's (OTC) September 27, 1994 Memorandum of Understanding (MOU) in Maryland. In accordance with the MOU, the revisions implement the Maryland portion of a regional NO<INF>X</INF> cap and trade program that significantly reduces NO<INF>X</INF> emissions generated within the Ozone Transport Region (OTR). EPA is approving these revisions in accordance with the requirements of the Clean Air Act.