I think that in the short-term, small private practices will still require the services of an external billing contractor. However, as a coding supervisor for a physician corporation with 90+ physicians who has been using EHR for over two years, I consider myself pretty knowledgable about what happens to the billing and coding status quo when providers begin to use electronic medical records. I remember several years ago when the software was installed, and we shrugged off ugly rumors such as, 'we aren't going to need the coders anymore'. The truth is, coders are still very much needed, but not in the same capacity as we were used before.
Our EHR has a feature called "automatic charge pass through" that allows the CPT and ICD-9 codes to drop from the EHR into a holding tank prior to claim submission. Billers and coders review this data to check on appropriate code-sets, modifier usage, and other issues that could cause claim denials. We have some fairly sophisticated claim edits in place to catch any billing errors before they are uploaded to our clearing house. The coders who used to look at every charge and manually post charges now all have other responsibilities, and unfortunately, we need fewer coders to accomplish them. There is very little manual charge entry, and even less manual payment posting. The entire revenue cycle can now be performed electronically, with very little manual effort and even fewer people-related errors, which reduces the need for front-end coding, charge entry, payment possting and A/R staff.
Even if your clients don't purchase an entire practice management system, most providers who purchase an EHR would be very unlikely to also purchase an additional (costly) license for their billing service; and likely would opt to bring the billing in-house, so that they won't have to re-create everything on paper. How many home-based billing services are going to be able to afford to purchase an EHR license for each of their accounts, not to mention the hardware and technical backup to support them? I think that a savvy coder/biller who is currently working for a billing agency should sharpen their auditing and education skills, because the EHR is not foolproof, and there is room for compliance concerns and documentation errors, which coders can help alleviate. Most operative notes can't be easily re-created by using EHR templates (yet), so surgical coders are still in demand.
As much as we might hope otherwise, eventually there will be federal requirements for EHR implementation, so I would recommend that nobody keep their heads in the sand at the risk of being in the same boat as medical transcriptionists; in our facility, EHR has virtually replaced the need for all transcription except operative notes. I do predict that as more physicians are financially enticed and eventually federally mandated to implement an EHR, the demand for an external billing service may decrease, but if you recognize that now, you'll have sufficient time to position yourself so that you will have the skills and abilities necessary to make a living in this field.
This is a fast-changing field, but hopefully we'll all figure out ways to contribute our talents and expertise as technology changes medicine.