According to The Royal Household:
At the end of The Queen’s 90th birthday year, Her Majesty will step down as Patron from a number of national organisations. The Patronages will be passed on to other Members of the Royal Family in the coming months.
Her Majesty is currently Patron of more than 600 organisations and has enjoyed a close and active association with a great number of them throughout her reign.
Her Majesty will continue to serve as Patron to hundreds of charities and institutions but will now share this work with her family.
To read the entire announcement from The Royal Household, please click here.