Social Security marks its 80th birthday Friday, and it’s an occasion that should be celebrated. But Social Security is showing its age, or rather, American workers are showing theirs. In 1960, there were more than five workers for every person receiving benefits; that ratio is now fewer than three workers for every beneficiary. With less money coming in and more being paid out, the Social Security’s trust funds, now valued at $2.8 trillion, are expected to be exhausted in 20 years when there will be only two workers for every retired person. After 2035, only enough payroll taxes would be collected to pay 79 percent of benefits, forcing an automatic 21 percent cut for the estimated 90 million Americans forecast to receive Social Security.

And Congress needs to address this quickly, particularly for the disability program, the reserves for which are expected to run out by late next year, at which point 19 percent cuts to benefits are possible. A temporary patch is available if Congress were to divert funds from the retirement reserves to the disability program, as it has done before. But a broader fix still is needed. There are possible remedies, which while not painless will ensure Social Security’s viability for many years to come:

Currently, the payroll tax of 12.4 percent is capped at $118,500 of a worker’s wages, meaning wages above that line are not taxed. Removing the cap would make up nearly two-thirds of the shortfall.

Increasing the payroll tax rate by a tenth of a percentage point each year until it reaches 14.4 percent, would cut nearly half of the shortfall.

Raising the retirement age — currently 66; 67 for those born in 1960 and later — to 68 by 2033, would cut 15 percent from the shortfall. Or raising the current early retirement age of 62 to 64 in 2023 and the full retirement age to 69 by 2027 would erase 29 percent of the shortfall.

Removing the cap, incrementally increasing the tax rate and raising the retirement age would more than cover the shortfall and also would allow for reform of the annual cost-of-living adjustment formula, a measure called the CPI for the Elderly, which more realistically acknowledges the increased costs the elderly incur for health care.

In the short-term Congress should ensure adequate funding for the disability program with an infusion from the retirement reserves. Doing so knocks a year off Social Security’s run-dry date from 2035 to 2034. But that stop-gap measure should be followed quickly with a more complete fix for the entire system.

Further delay limits the effectiveness of any solutions to which Congress can agree.