Covid-19 is altering the retirement time lines of a relatively small segment of older working Americans, according to a recent survey.

In fact, the pandemic has caused approximately one in eight U.S. adults over the age of 55, or 13%, to plan on delaying their retirement, according to the survey by Smart, a global digital retirement record-keeping platform that entered the U.S. market earlier this year. More than half of those who report planning to delay their retirement believe they will have to retire much later than expected.

The greatest proportion of the survey respondents, 39%, reported planning to retire between the ages of 65 and 69, while another 18% reported planning to retire between ages 70 and 79.

This is borne out by the timing of withdrawals from retirement savings. While most respondents, 39%, said they either plan to or already have first accessed their retirement savings between the ages of 65 and 69, an equal number, 16%, said they would begin to withdraw or had already withdrawn from their retirement savings between the ages of 60 and 64. Another 16% said the same thing for ages 70 to 74.

But the survey found that many Americans over the age of 55 aren’t thinking about retirement as a single point in time. More than two-fifths of the respondents, 42%, prefer to think of retirement as a process with several stages, and more than one-third, 34%, intend to work after they reach retirement age.

More than three-quarters of the survey respondents, 78%, said they were worried about their retirement finances. Both before and after the coronavirus stuck, Americans nearing retirement said paying for health-care costs was one of their top concerns—over half of the survey respondents mentioned the affordability of their health care as a financial concern before retirement.

Smart found that 43% of Americans over age 55 wanted help managing their retirement finances, while 38% said they preferred to go it alone.

For the survey, Smart commissioned YouGov to poll 2,654 U.S. adults online in November 2020.