TIAA-CREF Social Choice Bond applies social screens to its picks and leaps to the top of the pack. Thinkstock By Ryan Ermey, Associate Editor From Kiplinger's Personal Finance, April 2015 You’ve probably heard of socially screened stock funds. But bond funds that filter for good corporate citizenship? They’re much rarer in the world of what is commonly called socially responsible investing.See Also: Best Stocks for Socially Responsible Investors Social screens have hardly hindered TIAA-CREF Social Choice Bond (TSBRX), the top medium-maturity taxable bond fund over the past year. The fund invests mainly in high-grade debt, although it has 10% of its assets in junk bonds. As for social screens, managers Steve Liberatore and Joe Higgins look for bonds issued by firms that lead their industries in environmental awareness, corporate governance, and such things as product safety and treatment of employees. They also allocate a chunk of the portfolio, nearly 25% at last report, to “proactive social investments”—bonds or issuers that fund initiatives to address social issues such as public housing and climate change. The fund’s flexible approach allows the managers to get broad exposure to the market. With bond investing, says Liberatore, “you don’t get paid for picking winners. You get paid for avoiding losers.” The managers did pick a winner, in a way. Because of what Liberatore calls their “less than sanguine” view of the U.S. economy, they ratcheted up the fund’s interest-rate sensitivity by adding more long-maturity, high-quality bonds, including Treasuries. That gave the fund an extra boost relative to its peers as bond yields plunged over the past 13 months.