Buy I-Bonds Now or After May 1st?

This is a common question in April since we'll see new I-Bond fixed rate and inflation component come out on May 1st. If you're planning to keep I-Bonds for the long term, the fixed rate is most important, and unfortunately, no one knows the criteria used by the Treasury. This Bogleheads thread has an interesting discussion on this question.

If you don't plan on holding I-Bonds for the long-term, the inflation component becomes more important. We should know what this rate will be when inflation numbers for March come out in mid April. Based on this post at Savings-Bonds-Advisor, the rate is likely to be low.