Before ringing in the new year, millions of Americans may want to check in with their student loan servicers because they may be on the soon-to-be reported default list, experts said. More than four million Americans are technically in default, or at least 270 days overdue, on their student loans, said Michele Raneri, vice president and head of U.S. research and consulting at TransUnion. They just haven’t been reported to the credit bureaus yet for various reasons, including processing lags, she said. Whe ...