The trustees report chalked up the new projection to the recent slowdown in health spending growth and various cost-saving reforms enacted under Obamacare.
"In recent years U.S. national health expenditure (NHE) growth has slowed relative to previous historical patterns," the report read.
It added: "The Board assumes that the various cost-reduction measures ... will occur as the Affordable Care Act requires." (Obamacare has been credited in recent years with extending the life of Medicare beyond 2016, the year it was projected to go in the red prior to the ACA's enactment.)
The report said the health care law included provisions aimed at "reducing costs, increasing revenues, improving benefits, combating fraud and abuse" and other systemic changes. It cautioned that if the health sector "cannot transition" under Obamacare reforms to the delivery system and provider reimbursement rates, the availability and quality of care seniors receive would fall.
Notably, the trustees report also assumed -- for the first time -- that Congress would override planned reimbursement cuts to physicians under Medicare, which it has done regularly for more than a decade with so-called doc fixes.
The updated trustees report for Social Security found that its retirement and disability trust fund is projected to remain solvent through 2033, the same year as projected last year.