I am developing a database that will track monthly performance results. Each department will input their own departmental data. Aggregate reporting will follow. It been asked that I "lock down" all records that pre-date the current month. Intended result, once the numbers are published, someone can't go back and change them.
Can this be done ...and if so...How ?

Hi,
since you are displaying the info on form level try to do your evaluation on the form on open or on current event or so:

If Me.YourDate < DateAdd("m",-1,Date()) Then
Me.YourField01.Disabled = True
Me.YourField02.Disabled = True
Me.YourField03.Disabled = True
...
Else
Me.YourField01.Disabled = False
Me.YourField02.Disabled = False
Me.YourField03.Disabled = False
End If

You could also filter out all records in a query with a criteria like above mentioned and then lock the form which displays these records.
Then add a yes/no field to the table and set that to True ones it's published or whatever you are doing.
Then you can evaluate based on that to set them all enabled if they have a check...
HTH
Good luck

If I'm using DAO, which I am, can I set the recordset to READ ONLY based on your criteria above ?

You could also make queries to "Snapshots". Snapshots are read only and any subsequent object based on that query will also be read only for data that comes from that query. Or you can just make the form display snapshot...
HTH
Good luck