Table II.B1 shows the income, expenditures, and asset reserves for the OASI, the DI, and the theoretical combined OASI and DI Trust Funds in calendar year 2014.
The trust fund investments provide a reserve to pay benefits whenever total program cost exceeds income. Trust fund reserves increased by $25.0 billion in 2014 because total income to the combined funds, including interest earned on trust fund reserves, exceeded total expenditures. At the end of 2014, the combined reserves of the OASI and the DI Trust Funds were 308 percent of estimated expenditures
1 for 2015. In comparison, the combined reserves at the end of 2013 were 322 percent of expenditures for 2014.