Many people enter retirement earlier than planned and the transition is less gradual than expected, according to new research.

MassMutual Financial Group discloses these findings in a new survey, “Hopes, fears and reality: What workers expect in retirement and what steps help them achieve the retirement they want.” Conducted by Greenwald & Associates, the survey examines pre-retirees’ expectations and preparations for retirement and how those plans compare with actual experiences people have after they retire.

Nearly half of MassMutual’s survey respondents (45 percent) retired earlier than planned. The most frequently cited reasons for retiring early are changes at one’s company or place of work (44 percent) and being able to afford retirement (39 percent). Nearly 8 in 10 who retired early have no regrets about the decision to retire when they did.

“Despite pre-retirees’ typically wanting to work as long as possible, retirees discover that often, and suddenly, ‘work can retire you,’” the report states.

The survey adds that satisfaction with retirement lifestyle increases between the first 5 years of retirement versus 5-plus years since retiring (retired less than 5 years ago [56 percent), 5 to 10 years ago [63 percent] and 11 to 15 years ago [62 percent].

Concerns about retirement decrease as pre-retirees approach retirement. Nearly one-third of pre-retirees who are 11 to 15 years from retirement say they are looking forward to retirement, with few or no concerns. But, the research adds, this percentage grows to 43 percent for those less than 5 years way.

Only 63 percent of those retireing in 11 to 15 years believe they are on track toward being financially secure, but this percentage grows to 82 percent by the time individuals are less than 5 years from their expected retirement date.

Six in 10 retirees are very satisfied with their retirement lifestyle, the report adds. Satisfaction is greatest among those who are in their 70s, in good health and married/living with a partner, have at least $500,000 in assets and have a pension.

Most retirees feel financially secure and able to engage in the activities they enjoy at least as much as they had hoped, though 10-19 percent say they do not. Positive surprises about retirement include having few time constraints (23 percent) and keeping busy and active (18 percent), the survey adds.

Click here to view charts recapping survey results about respondents who retired later than planned and about the timing of their retirement.