Offering Circular Supplement (To Base Offering Circular dated January 1, 2002) $837,824,999 Government National Mortgage Association GINNIE MAE® Guaranteed REMIC Pass-Through Securities and MX Securities Ginnie Mae REMIC Trust 2003-018 The   securities The Securities may not be suita- ble   investments for   you.   You should   consider carefully  the risks of investing in them. See  "Risk  Fac- tors"   beginning on  page  S-9 which highlights some   of   these risks. The Trust will issue the Classes of Securities listed on the inside front cover. The Ginnie Mae Guaranty Ginnie Mae will guarantee the timely payment of principal and interest on the securities. The Ginnie Mae Guaranty is backed by the full faith and credit of the United States of America. The Trust and its Assets The Trust will own (1) Ginnie Mae Certificates and (2) cer- tain previously issued certificates. The  Sponsor  and  the  Co-Sponsor  will  offer  the  securities  from  time  to  time  in negotiated transactions at varying prices. We expect the closing date to be March 28, 2003. You should read the Base Offering Circular as well as this Supplement. The securities are exempt from registration under the Securities Act of 1933 and are "exempted securities" under the Securities Exchange Act of 1934. Salomon Smith Barney Myerberg & Company, L.P. The date of this Offering Circular Supplement is March 20, 2003. B-53