As of 2016, there is about $2.8 trillion in the Social Security Trust Funds, if you include what is owed to it by the Treasury for the bonds purchased with the surplus funds every year.
The funds in the Trust are partitioned from the rest of the government budget, but the surplus year to year is invested in Treasury Bonds which effectively gives the government temporary use of the funds in exchange for a market-value interest rate.
Disturbingly, current projections are estimating that the Social Security Administration will only be able to pay about 75% of its obligations by around 2037. The trust fund is not permitted to invest in anything other than government bonds, so a higher rate of return cannot be generated willfully.
There are currently 2.8 workers for every social security beneficiary, but there will only be about 2.2 workers for every beneficiary in a few years when more Baby Boomers enter retirement. The solution will probably come in the form of reduced benefits or more taxes on benefits for those with higher retirement income.
In 2016, about $57 billion a month is paid out in retirement benefits, about $11 billion a month in disability benefits, and about $7 billion a month in survivors’ benefits.