GOP lawmakers are questioning how senior citizen nonprofit concern AARP can bypass millions in tax levies despite the group's control over, and approval of, products sold by private firms.

Rep. David Reichert, R-Wash., one of several GOP members of the House Ways and Means Committee, claimed that companies that use the AARP brand to sell products such as insurance are helping the organization reap big profits and has sent a letter to the IRS calling the service's attention to the matter.

Critics have pointed out that AARP's income from United HealthCare alone rose from $284 million to $427 million between 2007 and 2009.

Appearing on Fox News, Reichert labeled those increases "dramatic."

In the letter to the IRS, lawmakers cited a number of examples of AARP's influence over United HealthCare, including its authority over United's operating plan and the direction it provides the carrier.

In a written statement to Fox, a representative for AARP said that the primary goal of the group was to uphold its standards and a make a detailed commitment to quality control on products offered in its name.