The trend is a result of shifting cultures in employment, as nearly a quarter of 25-34-year-olds have already had five or six employers, which the same as the lifetime average for those over 65, according to the charity.
Almost half of those who have lost a pension are also unclear as to how they lost track, while a fifth have disregarded the paperwork.
However, on realising they have lost track of their savings, nearly a quarter of survey respondents said they would contact previous employers for help, while 15% would contact the government or tax office.
Age UK head of services Lucy Harmer said: "While some measures are being taken by the government to account for smaller pension pots likely to be created under auto-enrolment, existing pots that we may already have are not being accounted for. This makes it more important than ever that we keep on top of what we have already accumulated."
Pensions minister Steve Webb previously acknowledged the concerns of lost pots which led to the suggestion of the pot follows member regime.
Earlier this year, the minister confirmed the Department for Work and Pensions would begin legislating on the concept shortly.
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Did you know that you can trace any lost pensions by contacting the Pensions Tracing Service via https://www.gov.uk/find-lost-pension You can fill in a form online. Act now to make sure you keep a track of what you are entitled to. And don't forget to get your State Pension Forecast to plan your retirement!