<ARTICLE> 5 <LEGEND> THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM MEDIMMUNE, INC'S YEARLY REPORT ON FORM 10-K FOR THE TWELVE MONTHS ENDED DECEMBER 31, 1999 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FILING </LEGEND> <MULTIPLIER> 1,000 <PERIOD-TYPE> 12-MOS <FISCAL-YEAR-END> DEC-31-1999 <PERIOD-END> DEC-31-1999 <CASH> 36,570 <SECURITIES> 233,824 <RECEIVABLES> 86,894 <ALLOWANCES> 0 <INVENTORY> 31,777 <CURRENT-ASSETS> 401,838 <PP&E> 87,452 <DEPRECIATION> 0 <TOTAL-ASSETS> 648,424 <CURRENT-LIABILITIES> 98,952 <BONDS> 10,366 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 679 <OTHER-SE> 536,400 <TOTAL-LIABILITY-AND-EQUITY> 648,424 <SALES> 356,815 <TOTAL-REVENUES> 383,375 <CGS> 90,193 <TOTAL-COSTS> 306,556 <OTHER-EXPENSES> 0 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 3,176 <INCOME-PRETAX> 86,276 <INCOME-TAX> (7,095) <INCOME-CONTINUING> 93,371 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 93,371 <EPS-BASIC> 1.47 <EPS-DILUTED> 1.33