It will also only be implemented for economy passengers - business-class and first-class passengers will not board in a manner any different from how they do now. Travellers with disabilities, unaccompanied minors and active-duty military personnel will not see any changes either.
The method is not new for the carrier - it reportedly used it up until 2017 and only changed it when it introduced a new basic economy seating procedure, obtaining a computer system that only supported a structure of five-group boarding.
Speaking to the New York Post, a spokesperson for the airline said it is reintroducing Wilma as it is using new technology which helps to separate passengers into more than five groups while boarding.
The news outlet reported the change may not seem like a lot, but it can make a large difference when it comes to flights being early, late or on time and could save the airline penalties.
United Airlines will make the change on domestic flights and some international flights from October 26.
It comes after the airline announced it will be adding more flights between various locations this year, which will see an increase of flights between the US, New Zealand and Australia.