Rankings are based on the date the oath of office was taken, except in cases when a Senator resigns after the election and the winner of the election is appointed to fill the remainder of the term. For Senators sworn in on the same date, seniority is determined by prior Senate service, followed by vice presidential, House, Cabinet and gubernatorial service, according to the Senate Rules and Administration Committee. If ties remain, seniority is based first on state population and then alphabetically, if there are two Senators from the same state. The panel provided the ranking information but as a matter of committee policy would not confirm the list.
On January 3, Sen. Kirsten Gillibrand, D-N.Y., raises her right hand as her son Henry messes up her hair while Vice President Joseph R. Biden Jr., delivers the ceremonial swearing-in in the Old Senate Chamber. Gillibrand's other son Theodore, lower right, looks on.
Each year since 1990, CQ Roll Call has reviewed the financial disclosures of all 541 senators, representatives and delegates to determine the 50 richest members of Congress. This year's report, derived from forms covering the calendar year 2012, shows it took a net worth of $6.67 million to crack the exclusive club.