Introduction This paper will discuss accounting treatment of common costs presented in the financial statements of Bill and Melinda Gates Foundation. Bill and Melinda Gates Foundation (B&MGF) based in Seattle, Washington is the fourth largest privately operated foundation established by William H. Gates and Melinda French Gates in 2000, after merger of two independent foundations led by Mr. Gates, with an initial capital endowment of US$126 million which grew to US$2bn in the first two years. It was later joined by Warren Buffet in 2006 who offered 10million Berkshire Hathaway Class B shares worth approximately US$35 billion in 2006 spread over multiple years through annual contributions of US$1.5bn. The foundation has been recognized as association of the second most generous philanthropists in America (Answers.com, 2006). The foundation operates three programs namely Global Health Program, Global Development Program and United States Program. The objectives through different programs are to help the poorest with the enduring challenges of food, health and education. Various initiatives have been undertaken in different countries to support the local population and uplift standards of life. In particular these include agricultural development, financial services for the poor, health care & insurance programs, education & global libraries, housing and HIV research (B&MGF, 2007). The foundation has proved to be a successful one with assets reaching up to US$38bn and still continuing to grow. With new CEO coming in as Mr. Jeff Raikes joins the foundation, it aims to build upon the works and same charisma of ex-CEO Ms. Patty Stonesifer. Accounting Period in Review The accounting period in review is the financial year of 2007 ending 31 December 2007 which has been reported in the foundation’s annual report 2007. Allocation of Common Costs The B&MGF consists of two separate legal and audited entities – Bill & Melinda Gates Foundation (‘Foundation’) and Bill & Melinda Gates Trust (‘Trust’). The earlier distribute money to grantees and the later manages the endowment assets. Because of the nature of the business and transaction between the two entities a consolidated financial statement is prepared which uses a basis for allocating common costs to each entity. We will consider such items in reference to B&MGF and form a basis for their allocation:  1. Grants Expenses: These include expenses to fund foundations operations and other direct charitable expenses, operating expenses and capital and program-related investments. All such expenses are summed off to indicate the aggregate expenses of the foundation’s programs.  2. Direct Charitable Expenses: These include fees paid for consultation required for the foundation’s programs. All such expenses are summed off to indicate the aggregate expenses of the foundation’s programs. The foundation has three separate programs as mentioned above. The annual report does not provide how the above cost is incurred and recorded for each of the three programs. Furthermore, direct charitable expenses are not prorated to each program. The financial statement is prepared to provide a simple and clear understanding of its users and