These days, investors of all ages are understandably concerned about socking away enough income and making the best investments today to ensure a comfortable retirement later in life.

Only 20 years ago, more than half of all American workers said they were on track to retire before they reached the age of 65. Today, only about 23% of Americans say they’ll be able to retire by that age.

But for those investors – and the financial planners they rely upon – who still plan to retire early – maybe in their 50s or early 60s –  here’s an interactive slide show featuring seven of the largest obstacles standing in their way.