The Committee for a Responsible Federal Budget sums up the annual report of Social Security trustees:

The Social Security program is only 13 years from insolvency, and action must be taken promptly to prevent an across-the-board benefit cut for many current and future beneficiaries. The Trustees project the Social Security OASI trust fund will deplete its reserves by 2033, while the SSDI trust fund will be exhausted by 2057. On a theoretical combined basis – assuming revenue is reallocated between the trust funds in the years between OASI and SSDI insolvency – Social Security will become insolvent by 2034. Upon insolvency, all beneficiaries regardless of age, income, or need will face a 22 percent across-the-board benefit cut, which will grow to 26 percent by the end of the projection window.

Delaying action until 2034 would make the needed tax increases or benefit reductions about one-quarter larger than if action were taken today. According to the Trustees, 75-year solvency could be achieved with the equivalent of a 27 percent (3.36 percentage point) payroll tax increase today but would require a 34 percent (4.20 percentage point) increase in 2034. Similarly, Social Security solvency could be achieved with a 21 percent across-the-board benefit cut today, which would rise to 26 percent by 2034. Cuts to new beneficiaries would need to be 25 percent today, but even eliminating benefits for new beneficiaries in 2034 would not be enough to avoid insolvency.