Sixty-one percent of respondents in a Hearts & Wallets survey released today said that not knowing when they will stop working was their biggest obstacle to planning for retirement.

In addition, 64 percent of respondents, who do not plan to retire within five years, said they have difficulty with retirement planning. This is up from 54 percent in 2012 and 50 percent in 2010.

The Hingham, Mass.-based research firm found the most difficult tasks for those polled included “identifying what year I might stop working” (61 percent); “estimating the required minimum withdrawals” from retirement accounts (57 percent); “deciding where to put savings” (54 percent); and “getting started saving and investing” (51 percent).

“Investors aren’t sure when their last job will be,” said Laura Varas, Hearts & Wallets partner and co-founder.

According to the survey, the biggest financial advice gaps are “knowing how to find the right resources” for retirement planning (40 percent); “handling market volatility” (38 percent); “choosing appropriate investments” (37 percent); and “determining appropriate insurance levels” (36 percent).

“There’s a real need for professional advice, even among more sophisticated investors,” said Chris Brown, Hearts & Wallets principal and co-founder. “More than 50 percent of all U.S. households currently aren’t getting the help to be prepared for whatever the future brings. Retirement saving is much more than regularly sending a portion of one's paycheck to a 401(k) provider, but how many young Americans realize this?”

The financial services industry can help workers address retirement planning unknowns by providing easier access to professional advice with fee-for-service pricing, teaching proven behaviors that helped successful savers, and helping individuals figure out when work opportunities may slow down, said Varas.

Hearts & Wallets based these findings from its 2014 study Engaging Investors: Reasons for Seeking Help and Taking Action, that analyzes data from over from 5,500 U.S. households.