You moved your roster over and the Lapsed view now holds six hundred names, most of whom stopped coming years ago. The ones you actually want to win back are buried. Care ended is the fix, and there are two ways to record it in bulk. Both write the same care ended fact you can add by hand on a patient.
Status columns in a patient file
In a patient import, map up to three columns. Status accepts active (also current, yes, open) or an ended word such as inactive, discharged, archived, closed, former, moved, transferred, completed or deceased. Status reason takes moved, completed care, transferred, deceased, practice ended care or other; if you leave it blank, the reason follows from the status word, and otherwise it is Other. Status date is when care ended, and blank means today.
Nothing here blocks a row. An unrecognized status, an unreadable date or a date in the future becomes a warning on that row: the patient still imports, either with no care-ended record or dated today. Uploading the same file again doesn't add the same record twice.
Close out patients not seen in a long time
If your old system has no status at all, owners and admins can use Close out patients not seen in a long time on the import page. Pick a Not seen since date in the past and a reason (any except Deceased), then press Preview. It tells you how many patients would be closed out. Only patients who have been seen, have nothing booked and aren't set to as needed are included, and each is dated their last attended visit.
Record for that count applies it. If anyone changed between your preview and the click, it refuses and asks you to preview again, so you never record a list you didn't review. Past sweeps are listed with their date and patient count, and Undo then Reopen reopens everyone that sweep closed.