In OHIP billing, "groups" are collections of one or more doctors who wish to have their claims collected and paid together for a variety of reasons:
The doctors are paid salary by the hospital
When you do need to use a group number, you'll need to add it to your care provider settings. Valid group numbers look like the following:
NOTE ABOUT SOLO BILLING
You do not need to enter "solo" as a group number as it's already built into the system. Solo claims are the default if you have no groups specified AND if you do have groups specified, you haven't set the preferred group to anything but solo. This means you don't enter "0000" or "Solo/SOLO/solo" into your list of group numbers. It's unnecessary.