An alternative to investing in CDs is investing in Treasury bills (can do through Treasury Direct or your brokerage account). Currently, the annualized yield for a Treasury bill is higher than the 5% you're seeing for a CD (the 6-month one is 5.11% on Schwab for example). And while interest on CDs is taxable at the federal and state level, interest on Treasury bills is exempt from state and local taxes. Could be advantageous if you live in a high income tax state.