50 million elderly and disabled Americans, is expected to remain at around 3 percent of GDP until 2019 before climbing to 3.5 percent of the economy by 2023, for a total of $1.1 trillion in spending.
Medicaid is forecast to grow to 2.2 percent of GDP by 2023 when it is projected to total $572 billion in federal spending and 84 million beneficiaries.
Social Security outlays, estimated to account for almost one quarter the government's spending next year, are projected to remain near 5 percent of GDP in most years through 2018 and then climb to reach 5.5 percent of GDP in 2023.
Despite forecasts for rising spending for Medicare and Medicaid, both are expected to grow more slowly per capita over the coming decade than they were just six months ago.
The change was due partly to expectations for lower enrollment and a larger number of young, healthier beneficiaries in the Medicaid coverage pooll.
It also reflected a slowdown in spending growth for Medicare's Part A hospital, Part B physician and Part D prescription drug benefits, as younger retirees from the baby boom generation have entered the pool of beneficiaries.