Can you help us figure the OID interest for 6 strip treasury bonds maturing 2023 to 2028?

[spootsie]

Our new broker has incorrectly reported the total face value of our 6 bonds as the line 8 OID interest for 2018 alone.  We have 13 Form1040's from 2003 on but not the original cost basis for these bonds.  It was never a problem for our previous broker. Can you help us figure these amounts with the info we do have?

[CherylW · Accepted solution]

It's an incredibly complex calculation.

I'm assuming that you purchased them after 1984.

The formulas begin on page 13 of IRS Publication 1212, Guide to Original Issue Discount (OID) Instruments:

https://www.irs.gov/pub/irs-pdf/p1212.pdf