The embargo period before an article is made available for free can vary from a few months to two or more years.
In a 2013 study, 77.8% of delayed open access journals analyzed had an embargo of 12 months or less.
[1][2] A journal subscription or an individual article purchase fee would be required to access the materials before this embargo period ends.
Many scholarly society journals have adopted the delayed access model.
The wide range in embargo lengths – and the fact that open access is both defined and intended as the state of immediate access – limits the meaningfulness of classifying journals as "delayed open-access" journals.