Mediacom Broadband 10-Q 2009 Q2 Quarterly report

Exhibit 32.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Mediacom Broadband LLC (the “Company”) on Form 10-Q for the period ended June 30, 2009 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), Rocco B. Commisso, Chairman and Chief Executive Officer and Mark E. Stephan, Executive Vice President and Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that:

(1) the Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

August 7, 2009	By:	/s/ Rocco B. Commisso
		Rocco B. Commisso
		Chairman and Chief Executive Officer
	By:	/s/ Mark E. Stephan
		Mark E. Stephan
		Executive Vice President and Chief Financial Officer