Social Security: What Would Happen If the Trust Funds Ran Out? [Updated June 12, 2019] [open pdf - 1MB]
From the Summary: "Social Security's receipts and expenditures are accounted for through two federal trust funds: the Federal Old-Age and Survivors Insurance (OASI) Trust Fund and the Federal Disability Insurance (DI) Trust Fund. Under their intermediate assumptions and under current law, the Social Security trustees project that the DI trust fund will become depleted in 2052 and the OASI trust fund will become depleted in 2034. Although the two funds are legally separate, they are often considered in combination. The trustees project that the combined Social Security trust funds will become depleted in 2035. At that point, the combined trust funds would become insolvent, because incoming tax revenue would be sufficient to pay only about 80% of scheduled benefits."
CRS Report for Congress, RL33514
Congressional Research Service: https://crsreports.congress.gov/