How do i treat savings bond interest from bonds that matured 5 years prior?

[Critter-3]

It is taxable interest in the year you cash in the bonds even if they matured years ago.  

[Hal_Al]

@Critter-3  Do you have a reference source for your answer?

I'm of the opinion that, to be technically correct, poster must file an amended return for the year the bonds matured and report the interest for that year.  But I can find no reference that says that directly. I base my opinion on the wording in Pub 550 (see below).

As practical matter, reporting the interest in the year the bonds are cashed is probably good enough since he will get a 1099-INT for that year.

From page 7 of Pub 550, emphasis added https://www.irs.gov/pub/irs-pdf/p550.pdf

Reporting options for cash method taxpayers. If you use the cash method of reporting income, you can report the interest on Series EE, Series E, and Series I bonds in either of
the following ways.
 Method 1. Postpone reporting the interest
until the earlier of the year you cash or dispose of the bonds or the year in which
they mature. 
Note. Series EE bonds issued in 1990
matured in 2020. If you have used method
1, you generally must report the interest
on these bonds on your 2020 return. The
last Series E bonds were issued in 1980
and matured in 2010. If you used method
1, you generally should have reported the
interest on these bonds on your 2010 return.
2. Method 2. Choose to report the increase
in redemption value as interest each year

[Critter-3]

Most folks never report the interest "as earned" method 2 ... if they did they would not allow a bond no longer paying interest to go uncashed.  So for those folks who did not use method 2  the interest is reported in the year it is cashed in ... that is the year the bank will report the interest to the IRS and is the path of least resistance.  Although the IRS pub says differently this is something they will never notice, catch or audit.  They are just happy the interest is reported at all and were thrilled that the bonds were not cashed in earlier and they got interest free use of the money for years.

[david01238]

Thanks, You are where I was at when I posted the question. I am looking at 5 years of amended returns for about $1000 each year. None would change my Medicare IRMAA. Last years would be in a lower tax bracket but would not change any relief checks and the tax bracket change would be minimal. I like your thought that "as a practical matter just file it this year." If I don't get any other advice, I will likely do that.