Even without much help from an employer-sponsored defined benefit plan such as CSRS or FERS, the combination of Social Security plus personal retirement savings can go far toward retirement security–but discipline is needed to make those savings over a long time, a study has found.

The Employee Benefit Research Institute said that more than four-fifths of workers participating in plans such as 401(k)s–or their equivalents such as the TSP–would be able to replace at least 60 percent of their pre-retirement income after age 64, counting Social Security, if they participated in such plans for at least 30 years.

Sixty percent of pre-retirement income is considered by many financial experts to be on the low end of what is needed in retirement, with up to 80 percent or even more often cited as a goal. The study said that around three-fourths of workers under the same assumption would be able to achieve a 70 percent replacement level and about two-thirds could achieve 80 percent.

The key, however, is actually participating in such plans by taking advantage of them as soon as possible–for example, starting on hiring–and investing enough to capture the maximum available employer contributions.

The study added that the presence of a defined benefit plan in addition to those two sources of income increases confidence of not running short of money in retirement by about 12 percentage points.