Here's the code, commented line by line for better understanding.
Code:
Sub UpdateIntakeDate()
Dim rng As Range 'the overall range to work on
Dim cel As Range 'the one cell to work on at a time
Dim lr As Long 'the last row with data in the column
With Sheets("Client Tracker")
'determine last used row in the column
lr = .Cells(.Rows.Count, "E").End(xlUp).Row
'if lr is less than first row that would have dates don't go any further
If lr < 6 Then Exit Sub '<<<<<<<<<<<<<
'set the range to work on
Set rng = .Range("E6:E" & lr)
'work on the cells in the range one at a time
For Each cel In rng
'if the cell IS NOT blank
If cel <> "" Then
'check if today is greater than or equal to the date in the cell plus one year
If Date >= DateAdd("yyyy", 1, cel) Then
'if it is then give it the new date
cel = DateSerial(Year(Date), Month(cel.Value), Day(cel.Value))
End If
End If
'move on to the next cel by going back to the start of For Each
Next cel
End With
End Sub