That's a reserved word and a bad choice of fieldname.

That's another reserved word and also a bad choice of fieldname.
You'll need to ALWAYS enclose both these names in [square brackets] or
Access *will* get confused!

Neither VBA nor VBS (??) is needed: you can put a calculated
expression in a query. Note that a "combo field" is apparently an
instance of the dreaded and despised "Lookup Field" - the table does
NOT containwhat it appears to contain ("Revision" or "Review"), it
contains a concealed numeric link to the lookup table. I don't know
what that table might be named so I can't include it in a sample
query. Mixing in the lookup table makes my idea of a simple DMax()
function call problematic!

Instead, create a Query joining your main table to the lookup table.
Select the field that contains "Review"/"Revision" and put a criterion
on it of

IN("Review", "Revision")

to select just those two options. Select the [DATE] field and whatever
field you want to group by (I presume that this table contains
information about Projects or something similar and you want the
latest date for each project?)

Change the query to a Totals query by clicking the Greek Sigma icon
(looks like a sideways M). Group By this field; use WHERE as the
totals operator on the Type field; Group By the Project ID (whatever
it is); and select Max on the Date field. This will give the latest
review or revision date (whichever is later) for each project. Include
this Totals query in your report's recordsource query, joining by
ProjectID.

You can then use a textbox on your report with

=DateAdd("yyyy", 1, [MaxOfDate])

to calculate the next due date.

                 John W. Vinson[MVP]    

many thanks for the advice.  I'll change the field names so that they don't
confuse Access.