Rule 424(b)(3) Registration No. 333-57813 NEXTLINK COMMUNICATIONS, INC. PROSPECTUS SUPPLEMENT DATED MARCH 3, 2000 TO PROSPECTUS DATED JULY 24, 1998 The Selling Stockholders table on pages 16-17 of the Prospectus is hereby amended as follows to include additional Selling Stockholders: Number of Shares of Selling Stockholders Preferred Stock - -------------------- --------------- Merrill Lynch Pierce Fenner & Smith Inc. 17,500