The reforms, brought in four years ago, gave pension savers access to their pots from age 55 and opened up the drawdown market, according to a new Openwork survey of UK advisers.
The survey of 115 UK financial advisers focused on adviser views on pension freedom and found more than half (51%) believed access to advice needed to improve to ensure the reforms continue to work well.
Some 56% also said they worried about low levels of consumer understanding despite the reforms being in operation for the past four years.
Retirement income advice was shown to be a boom area for advisers with 68% reporting an increase in demand for their services in the past year."
Openwork said its advisers were also concerned about the increased use of drawdown, with more than two-thirds (68%) of advisers saying non-advised drawdown was their biggest worry after four years of pension freedom.
Elsewhere in the survey, retirement income advice was shown to be a boom area for advisers with 68% reporting an increase in demand for their services in the past year.
Retirees running out of money was identified as the biggest adviser worry by more than a fifth of respondents (22%), followed by 18% who feared further government changes to pension rules.
Openwork wealth and platform director Mike Morrow said: "Pension freedoms have been a success based on the numbers of people wanting to access their money and the demand to take cash out of pensions.
"But four years down the line there are continuing worries about how well it is working in practice for retirement savers and advice is the missing link for making it a complete success.
"Retirement savers need help in making sure they receive the best value from their pension funds and increasing access to advice is vital to help maintain confidence in the system. The government could also play its part by resisting the temptation to tinker with pensions regulation."
HM Revenue & Customs figures show more than £35bn has been withdrawn from pension funds by over-55s since the launch of pension freedoms with £2.3bn withdrawn in the first three months of this year.