"That more than half of Americans with above-average savings feel that they have inadequate retirement savings is a nationwide problem that needs to be addressed. These concerns coming from investors will only be magnified when looking at the general population," comments David Siegel, CEO of Investopedia. "Retirement is repeatedly cited as the top financial concern for Americans and yet it's clear they're still not receiving the necessary tools and advice to succeed. The first step to alleviating this burden and getting people on track is education. Financial literacy is not just an individual issue but one that impacts a country's economy, and we urge schools, communities and government organizations to make it a top priority."

The study, Retirement in America: The Search for Security, revealed other key insights about investors in the United States over the age of 18 who have input into their household investment decisions. Respondents who self-identified as being behind, on track and ahead all use employee-sponsored retirement plans at the same rate. Additionally, 78 percent of those who feel they are behind currently contribute to an employee-sponsored plan, indicating that saving through a 401(k) or 403(b) is not enough to stay on track.

Nearly four out of five investors participate in some form of retirement plan though only 18 percent receive professional advice. Only 10 percent of those surveyed feel they are ahead in their retirement savings. Contributing to an individual retirement account is the biggest differentiating factor for those who feel ahead of schedule. Eighty-two percent of ahead-of-schedule respondents indicated contributing to an IRA. Twenty-eight percent of respondents agreed that they were on track. The remaining 10 percent of respondents stated they were unsure about the status of their retirement savings.

The level of income for respondents does not appear to be a driving force behind retirement savings. Investors who say they are ahead have more than five times the investable assets of those who feel behind while earning less than two times the average income.

The study also revealed specific strategies and concerns about Americans' retirement savings:

• 38 percent of respondents feel they are on track or ahead of schedule
• 82 percent of investors who feel ahead on their savings contribute to an individual retirement account, compared to 57 percent (on-track) and 33 percent (behind)
• 60 percent of respondents aged 50+ are worried that something may delay their retirement - with healthcare costs as the top concern
• 82 percent of respondents receive no retirement advice from a financial professional
• 81 percent of millennials do not have confidence that Social Security will be available when they reach retirement age

"It's great to see that four out of five respondents are engaged in at least some type of retirement savings, but the evidence shows it is clearly not enough," adds Siegel. "With only 18 percent of investors receiving professional advice, the majority of Americans need as many tools as possible to independently navigate this tricky landscape, especially those least confident in their plans. Those turned out to be respondents between ages 35 and 49. This is the most crucial time for investors to get their retirement savings on track and that should ideally be a much higher percentage. This is why Investopedia continues to expand our content to include access to professional advisors, webinars, tutorials and timely news relevant to every stage of an investor's life and especially retirement."