I am going through and doing an Investment Securities audit for the first time and need a little help. I have reconciled the transactions back to the general ledger but I need to know how to recompute the accretion/amortization of discount/premium using the interest method and recalculate the amortized cost of selected securities. Any help would be appreciated.

do a google search for bond amortization - you just need to develop a spreadsheet, it won't be too hard. if you can amortize a loan, you can amortize a bond.

Also, pay close attention to what the security is classified as: trading, held to maturity, or available for sale. Depending on how a security is classified changes how it's accounted for.