When President Ronald Reagan signed the Federal Employees’ Retirement System Act in 1986 flanked by a bipartisan, bicameral group of lawmakers, the intent was clear: to provide federal employees a defined contribution retirement plan like private employers’ 401(k) plans. The Thrift Savings Plan has grown to hold the retirement savings of more than 5.5 million participants from federal and military service, with total assets of $600 billion.

The statute creating the Federal Retirement Thrift Investment Board directed the governing board to select indexed investment funds that would offer participants best in class investment opportunities, and provide them with the options to help them maximize their hard-earned retirement savings. Recently, the TSP board has been urged to consider issues beyond those focused on investing for retirement, involving the appropriateness of certain foreign investments.

TSP funds are solely the property of plan participants—it is not federal money and it is not taxpayer money. Choices on how to invest in the TSP funds belong solely to the participants. The FRTIB is required by Congress to make decisions that are in the best interest of all TSP participants, and not consider issues better left to other federal entities.

After being asked to reconsider moving the international (I) fund to track the MSCI All Country World ex USA Investable Market Index, a broad international index that includes investments in Canada as well as a variety of emerging markets including China, the TSP board took a second look.

Based on the best investment advice available and consistent with our legal mandate, the FRTIB decided on Nov. 13 to continue forward with a move to the broader international index. In so doing, the TSP will match what all the top 10 of the largest U.S. companies’ 401(k) plans offer, what all the top 10 federal contractors’ 401(k) plans offer, what all six of the six largest target date fund providers offer, as well as what all 20 of the largest public employee benefit plans for state employees offer. Moving to the new benchmark could improve the expected return and diminish the expected risk for participants.

This decision fell squarely within the TSP board’s mandate. We believe this fund should be offered as an option for all TSP participants. But as with all other funds, the choice to invest in the international fund would rest solely with participants.

The Office of Foreign Assets Control within the Treasury Department enforces economic and trade sanctions based on U.S. foreign policy and national security goals against targeted foreign countries and regimes. In other words, OFAC is responsible for determining which countries and companies are not suitable trading or business partners for the United States.

If a comprehensive ban on investing is issued by OFAC, that entity would be dropped from the index. No U.S. investors— whether their funds were in the TSP I Fund or elsewhere—could invest in those companies. Action by OFAC would ensure that U.S. interests are protected and that there is a level playing field for all Americans who are investing and saving for their retirement.

All investors, whether they are public servants or not, should examine their investment portfolios to make sure that they have made smart decisions that are in keeping with their retirement timeline and their personal conscience. Based on current best practices in the investment industry and the mandate given to us by Congress, we don’t believe it’s appropriate to prohibit millions of TSP participants from making a choice that could be in their best interest and is available to all other American investors.

Michael Kennedy is chairman of the Federal Retirement Thrift Investment Board and Clifford Dailing is chairman of the Employee Thrift Advisory Council, a 15-member advisory board composed of federal and postal employee unions and management associations.