In June, the first full month that museums were open again, more than 411,000 visits were made to museums by Museum card holders.
However, the figures are lagging behind on previous years and the Museum Association therefore expects a long recovery period.
Museums and their collections are at risk if there is no more corona support from the government than has been promised so far, the association said.
The number of visits with the Museum Card is more than a third lower than in 2019.
The sale of the number of single tickets is also lagging, partly because there are few foreign tourists and there is a lot of competition on the leisure market.
An earlier study by the Museum Association, conducted after the first lockdown, already showed that the number of museum visits is one of the last things to return to the old level.
In addition, most museums allow a limited number of visitors.
Only a few use Testing for Access and the CoronaCheck app, allowing more people to enter.
However, there is not much enthusiasm for this among the public.
The exact figures of the number of individual tickets sold are not known to the Museum Association, but "it is obvious that the decrease is even stronger there", says spokesperson Janneke Visser.
Due to the disappointing sales figures, the association is therefore making an urgent appeal to the outgoing cabinet to also implement the support packages in the fourth quarter. "In 2022, due to the after-effects of the pandemic, recovery support will also be necessary," according to the Museum Association.