If you have the "Online RA" role in the Provider Web Portal at https://www.or-medicaid.gov, you can stop the paper RA by clicking the "Stop Paper RA" button when you first access the Online RA screen.
If you do not have Provider Web Portal access, you can also contact Provider Enrollment (800-336-6016) and ask to stop receiving the paper RA. Please provide the Provider ID listed in the "Payee ID" or "NPI ID" field in the top right corner of the paper RA.