A third of Americans plan to retire on Social Security alone, but it may not be enough to get by

• A third of US adults believe Social Security income alone will be enough for retirement.
• A financial expert advises building a 401(k) and HSA to prepare for unexpected expenses.
• A new NerdWallet report shows that the majority of Americans lack sufficient retirement savings.

America's retirees have a lot on their minds.

About a third of US adults believe Social Security alone will provide enough income for them to live comfortably in retirement, but another third said they won't have a retirement account to pull from when they leave the workforce.