Moody's reported on Wednesday that the U.S. government's current fiscal position remains healthy but if there aren't policy changes, there will be long-term risks from social spending that could affect the nation's credit standing.
Spending, especially for and Social Security programs, will cause a rise in future deficits and debt levels toward the end of the decade, Moody's said. An aging population will contribute to rising cost and demand for health-care services.
The report called for additional revenue, which could be realized from a higher-than-expected U.S. economic growth rate or policy changes such as an increase in Medicare premiums and co-payments.
Read MoreHow much more you'll get in Social Security next year