Is There Anything Else I Should Know About I Bonds?

Yes.  The Bureau of Labor Statistics reports the CPI-U.  The Bureau of Labor Statistics operates independently of Treasury and Treasury has no control over the determination, calculation, or publication of the index.  The regulations for the I Bond set forth the actions Treasury will take in the event the CPI-U is revised, rebased, discontinued, or fundamentally altered.  In addition, there can be a significant lag between the date the CPI-U is determined and interest is credited to an I Bond.