Hi Tia
Open the form in design view.
Right click on the grey section of the form (below to space where you put
your buttons, box, lists, etc)
On the dropdown box select Event
Select On-Open
Click the build options (three dots on the right)
Select Code
You will see this
Private Sub Form_Open(Cancel As Integer)
End Sub
Insert one line of code (DoCmd.Maximize)
So that your code looks like this
Private Sub Form_Open(Cancel As Integer)
DoCmd.Maximize
End Sub
Click Save and close your form.
When you open it again it "should" stay maximixed.
Hope this helps