There are various places that control Medicare Online printing. To turn them off see below:
Go in to File Menu -> Accounting Setup and turn off Print Batch (DB1) and set the Medicare and Vet Affairs Copies to 0, and click OK.
Then File Menu -> General Options and under Funds and ECLIPSE turn off Print IMC Declaration and Print IMC Invoice, and click OK.
Find the Medicare Online icon in the taskbar notification area (it's a little green square near the clock), right click it and go to Options, and untick Print DB1/D1217.
Even if you don't get the above right, you can still actually untick Print Batch when you're in the Batching screen. Or when you're billing you can just change the copies to 0.
You may also like to use a PDF printer, as that way you have a soft copy for printouts. Hard for us to say definitively if you have one installed (talk to your IT if unsure) but if you do then it's a matter of going to File Menu -> New Printer Setup, choosing All or All Common and then just choosing that PDF Printer from the printer drop-down, then clicking OK.