How is Social Security funded?

Social Security’s revenue was about $957 billion in 2016. The program has three sources of income. The largest source comes from workers and employers who contribute 6.2% each on wages up to $127,200 a year; this raises 87% of the total. The second source is investment income from Social Security’s reserves, which are held in Trust and invested in interest-bearing U.S. treasury bonds; this raises 9% of total revenue. Finally, Social Security gets 3% of its revenue from the taxes that beneficiaries pay on their Social Security benefits.