I have TreasuryDirect set up to purchase $X in I-bonds quarterly. It's been set and forget. I consider them the "medium term" component of my emergency fund, rather than an investment I expect significant yield from. They generally perform better than CDs, worse than corporate bonds, and are inflation protected. They're not too bad tax-wise either. The interest is subject to Federal income tax but not state or local tax. All of the above have their place in a well-diversified savings strategy.