There are only 2 ways to put money into a Roth IRA: (1) an annual contribution, which must be based on earned income and can only be made up to a set dollar amount annually; and (2) a conversion from a traditional IRA, which requires immediate income recognition of the converted amount (assuming the account was funded entirely with deductible contributions). Amounts that must be taken as required minimum distributions (RMDs) are not eligible for conversion. Only amounts exceeding the RMD can be converted.
The difference between the face value of a bond and its original issue price. OID is reported on an annual basis as interest income.