EHR parallel run: how to run old and new EHRs side by side
To run old and new EHRs side by side, make the new system the only place for new work from go-live, keep the old system open read-only for lookups and open claims, and spot-check charts in both until the reconciliation report is signed off. Agree what ends the parallel run before cutover, so the old system is retired on a plan.
- From go-live, book, chart and bill new sessions only in the new EHR.
- Keep the old EHR read-only for lookups, open claims and reconciliation checks.
- Agree before cutover what ends the parallel run and who signs it off.
What is a parallel run in an EHR switch?
A parallel run is the period after cutover when both systems are open but only the new one takes new work. The old EHR stays available for reference and for claims it already sent. The new EHR holds every new appointment, note and charge. The glossary entry for parallel run gives the short definition.
What stops in the old EHR, and what stays open?
| Task | Old EHR during the parallel run | New EHR |
|---|---|---|
| New appointments | Stop at the data freeze | Book here from go-live |
| New notes | Stop at the data freeze | Write here from go-live |
| New claims | Stop at the data freeze | Submit here from go-live |
| Claims sent before cutover | Work to a close where possible | Record what remains as an opening balance |
| Past records | Read-only lookups | Compare the migrated copy with the old one |
| Reports | Run counts and aging reports | Run the same reports to compare |
How do you run old and new EHRs side by side?
Step 1: Set the rules before cutover
Write down which tasks stop in the old system at the data freeze, which stay open, and who can still log in. Share the list with staff when you prepare them for cutover.
Step 2: Limit access to the old system
Ask your current vendor whether user accounts can be set to read-only. If they cannot, limit logins to the people who still need lookups and billing follow-up, and keep a list of who has access.
Step 3: Make the new EHR the only place for new work
Book, chart and bill new sessions only in the new system from go-live. If something is entered in the old system by mistake, note it and enter it in the new one the same day.
Step 4: Work open claims to a close in the old system
Follow up claims sent before cutover from the old system where possible, and carry what remains as opening balances, as covered in how to move client balances between EHRs. Billing one session from both systems can send the same claim twice.
Step 5: Spot-check charts in both systems
Open a sample of charts for every clinician in both systems and compare notes, diagnoses, documents and appointments. Log each difference against the reconciliation report.
Step 6: End the parallel run on a plan
End the parallel run when the reconciliation report is signed off, open claims are closed or carried as balances, and a final export is stored in your archive. Then work through when you can retire the old system.
What goes wrong in a parallel run?
- Staff keep booking or charting in the old system out of habit.
- A session gets billed from both systems.
- Changes made in the old system after the freeze stay out of the new one.
- The parallel run has no end conditions, so the old system stays open with no decision on when to retire it.
Frequently asked questions
What is a parallel run in an EHR migration?
A parallel run is the period after cutover when the old EHR stays open read-only for lookups and open claims, while all new appointments, notes and claims go into the new EHR.
How long should a parallel run last?
It depends on how long your open claims take to close, when the reconciliation report is signed off and when your old contract ends. Set the end conditions before cutover and review them each week.
Should staff enter data in both systems?
Staff should enter new work in the new EHR only. Entering the same session in both systems creates two versions of the record and can bill the session twice.
What happens to the old EHR when the parallel run ends?
Take a final export, confirm you can open it, store it in your archive and then cancel on the date your contract allows. What to do with your old EHR account after cutover covers each step.
For the full project from inventory to archive, see the EHR data migration guide.
How Ferry helps
Ferry migrates data between behavioral health EHRs at a fixed price, with a reconciliation report for every record type. Get a migration quote.