TWELFTH AMENDMENT TO THE AARP HEALTH INSURANCE AGREEMENT: PHIP EXTENSION

EXHIBIT 10(a)

TWELFTH AMENDMENT TO THE AARP HEALTH INSURANCE

AGREEMENT:

PHIP EXTENSION

This Twelfth Amendment to the AARP Health Insurance Agreement (“Twelfth Amendment” or “Amendment”), effective as of June 30, 2005 (the “Effective Date”), is made by and between AARP Services, Inc., a Delaware corporation (“ASI”) and United HealthCare Insurance Company, a Connecticut corporation (“United”). The parties hereto shall collectively be referred to as the “Parties”.

RECITALS

WHEREAS, AARP, the Trustees of the AARP Insurance Plan (“Trustees”), and United are parties to a certain AARP Health Insurance Agreement dated as of February 26, 1997 (the “Original Agreement”).

WHEREAS, by subsequent amendment and assignment on December 28, 1999, AARP, AARP Trust and United agreed to the assignment to and assumption by ASI of certain rights and obligations (the “Third Amendment”).

WHEREAS, various other amendments have been made to the Original Agreement (collectively, the “Agreement”).

WHEREAS, pursuant to the Ninth Amendment to the Agreement, the Parties have successfully piloted a program offering comprehensive insurance products for AARP members age 50 to 64 (“50-64 Plan”).

WHEREAS, the Pilot Period, as defined in the Ninth Amendment, expires on June 30, 2005; and

1

WHEREAS, the parties wish to extend the Pilot Period through December 31, 2005.

NOW, THEREFORE, the Parties agree as follows:

“2.134. Pilot Period means January 1, 2004 until December 31, 2005. The Pilot Period may be changed upon mutual written agreement. Any 50-64 Plan sales effective as of the end of 2003 and their experience will be included as part of the Pilot Period.”

IN WITNESS WHEREOF, the Parties have executed this Amendment as of the date and year first above written.

2