Rule 424(b)(3) Registration No. 333-57813 NEXTLINK COMMUNICATIONS, INC. PROSPECTUS SUPPLEMENT DATED MARCH 23, 1999 TO PROSPECTUS DATED JULY 24, 1998 The Selling Stockholders table on pages 16-17 of the Prospectus is hereby amended to (i) update the information regarding the following entities included in the Prospectus and their respective number of shares of Preferred Stock and (ii) include additional Selling Stockholders: Number of Shares of Selling Stockholders Preferred Stock - -------------------- --------------- Lindner Dividend Fund 855,000 Salomon Smith Barney Inc.(1) 392,000 Lindner Utility Fund 35,000 - ---------- (1) Formerly included as a Selling Stockholder under the name Smith Barney Inc.