UnitedHealth Group (UNH)

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Certification of Principal Executive Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended March 31, 2008 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Stephen J. Hemsley, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(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.

Date: May 2, 2008

Certification of Principal Financial Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended March 31, 2008 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, George L. Mikan III, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(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.

Date: May 2, 2008

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Certification of Principal Executive Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended September 30, 2007 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Stephen J. Hemsley, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(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.

November 1, 2007

Certification of Principal Financial Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended September 30, 2007 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, George L. Mikan III, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(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.

November 1, 2007

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Certification of Principal Executive Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended June 30, 2007 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Stephen J. Hemsley, President and Chief Executive 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 to my knowledge:

(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 6, 2007

Certification of Principal Financial Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended June 30, 2007 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, George L. Mikan III, 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 to my knowledge:

(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 6, 2007

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Certification of Principal Executive Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended March 31, 2007 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Stephen J. Hemsley, President and Chief Executive 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 to my knowledge:

(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.

May 9, 2007

Certification of Principal Financial Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended March 31, 2007 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, George L. Mikan III, Executive Vice President and Chief Financial Officer of the Company of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(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.

May 9, 2007

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended September 30, 2006 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Stephen J. Hemsley, President and Chief Executive 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 to my knowledge:

(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.

March 6, 2007

CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended September 30, 2006 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, George L. Mikan III, 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 to my knowledge:

(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.

March 6, 2007

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Certification of Principal Executive Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q/A for the period ended March 31, 2006 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Stephen J. Hemsely, President and Chief Executive 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 to my knowledge:

(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.

March 6, 2007

Certification of Principal Financial Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q/A for the period ended March 31, 2006 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, George L. Mikan III Chief Financial Officer of the Company of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(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.

March 6, 2007

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Certification of Principal Executive Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended June 30, 2006 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Stephen J. Hemsley, President and Chief Executive 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 to my knowledge:

(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.

March 6, 2007

Certification of Principal Financial Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ended June 30, 2006 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, George L. Mikan III, Chief Financial Officer of the Company of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(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.

March 6, 2007

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Certification of Principal Executive Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ending March 30, 2006 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, William W. McGuire, M.D., Chairman and Chief Executive 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 to my knowledge:

(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.

Certification of Principal Financial Officer

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ending March 30, 2006 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Patrick J. Erlandson, 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 to my knowledge:

(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.

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Certification of Principal Executive Officer

In connection with the Annual Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-K for the period ended December 31, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, William W. McGuire, M.D., Chairman and Chief Executive 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 to my knowledge:

(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.

Certification of Principal Financial Officer

In connection with the Annual Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-K for the period ended December 31, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Patrick J. Erlandson, 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 to my knowledge:

(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.

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ending September 30, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, William W. McGuire, M.D., Chairman and Chief Executive 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 to my knowledge:

(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.

November 4, 2005

CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ending September 30, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Patrick J. Erlandson, 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 to my knowledge:

(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.

November 4, 2005

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ending June 30, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, William W. McGuire, M.D., Chairman and Chief Executive 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 to my knowledge:

(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.

CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ending June 30, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Patrick J. Erlandson, 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 to my knowledge:

(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.

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ending March 31, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, William W. McGuire, M.D., Chairman and Chief Executive 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 to my knowledge:

(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.

In connection with the Quarterly Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-Q for the period ending March 31, 2005 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Patrick J. Erlandson, 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 to my knowledge:

(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.

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Certification of Principal Executive Officer

In connection with the Annual Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-K for the period ended December 31, 2004 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, William W. McGuire, M.D., Chairman and Chief Executive 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 to my knowledge:

(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.

Certification of Principal Financial Officer

In connection with the Annual Report of UnitedHealth Group Incorporated (the “Company”) on Form 10-K for the period ended December 31, 2004 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Patrick J. Erlandson, 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 to my knowledge:

(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.