<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY INFORMATION EXTRACTED FROM THE CONSOLIDATED
STATEMENTS OF OPERATIONS AND CONSOLIDATED BALANCE SHEETS OF MEDIACOM LLC AND
ITS SUBSIDIARIES AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0001064116
<NAME> Mediacom LLC
<MULTIPLIER> 1,000
<S> <C>
<PERIOD-TYPE> 9-MOS
<FISCAL-YEAR-END> DEC-31-2000
<PERIOD-START> JAN-01-2000
<PERIOD-END> SEP-30-2000
<CASH> 2,923
<SECURITIES> 9,797
<RECEIVABLES> 5,044
<ALLOWANCES> 774
<INVENTORY> 13,759
<CURRENT-ASSETS> 0
<PP&E> 846,173
<DEPRECIATION> (184,940)
<TOTAL-ASSETS> 1,279,087
<CURRENT-LIABILITIES> 0
<BONDS> 0
0
0
<COMMON> 0
<OTHER-SE> 296,039
<TOTAL-LIABILITY-AND-EQUITY> 1,279,087
<SALES> 244,513
<TOTAL-REVENUES> 244,513
<CGS> 83,813
<TOTAL-COSTS> 286,246
<OTHER-EXPENSES> 1,224
<LOSS-PROVISION> 0
<INTEREST-EXPENSE> 51,461
<INCOME-PRETAX> (94,418)
<INCOME-TAX> 0
<INCOME-CONTINUING> (94,418)
<DISCONTINUED> 0
<EXTRAORDINARY> 0
<CHANGES> 0
<NET-INCOME> (94,418)
<EPS-BASIC> 0
<EPS-DILUTED> 0
</TABLE>