Are I-Bonds Still Worth Buying in 2025 When Your High-Yield Savings Account Pays 4.5%? The After-Tax Math on $10,000
Series I savings bonds had a legendary run when inflation spiked in 2022 — the composite rate hit 9.62% for six months, and everyone was talking about I-Bonds. In 2025, the rate has settled to approximately 3.1%-3.5%, and online high-yield savings accounts are offering 4.2%-4.8% APY with zero lock-up period. On the surface, HYSA wins. But the real comparison requires after-tax math — I-Bonds are exempt from state and local income taxes, and for someone in California or New York, that exemption meaningfully closes the gap. Here is the complete comparison with real numbers, the four scenarios where I-Bonds still win in 2025, and the four scenarios where the HYSA is clearly the better choice.










