EHR would be classification of software. It would be like coming on GH and saying "hey guys I need an input device, any ideas?" without even specifying if its a keyboard or mouse you are after. Mental health providers have different need than general practitioners for example.
If you are not spam start here:
https://www.healthit.gov/If you are billing fed or state sources there are 'incentive' programs laid out from the HITECH Act (or other state-specific) that reduce the hair-cut you are taking on those reimbursements. For example, if you are billing medicare, you are already loosing a 2% haircut on reimbursement and that will be going to 3% next FY.
If you are in the SE of USA I run a small consulting firm. Most of our clients are in the 10K~15K unique clients/year range so you'd need to see if all the work and headaches of standing up an implementation makes sense for you. At that volume 2% loss is inching up over $1M in lost revenue.
We know a lot about the 'SEC' state rules, but literally every state has their own special rules and standards.