The Business Roundtable, which represents chief executives of major U.S. companies, proposed shoring up Social Security and Medicare by raising the eligibility age without increasing taxes on income subject to the Social Security payroll tax.

For Social Security, the group’s plan released today in Washington would gradually raise the retirement age to 70 from 67, scale back benefits for wealthier recipients and switch to a method of calculating inflation that would result in lower cost- of-living payments for current and future retirees.