While the actual certification of specific EHR systems and modules is still pending, and first requires at least one testing and certification body to be approved by ONC so there will be a way for vendors to get their products certified as compliant for meaningful use, there is no inherent restriction as to the size of the product or the market it which it's intended to be used. There are well over 200 EHR products in the market, some subset of which will seek certification and therefore help eligible providers qualify for incentive funding under meaningful use. It seems likely that in addition to products that will be installed locally within provider facilities, some certified EHR products will be provided as hosted or managed services that might be more attractive to small practices. ONC seems to be well aware that a large proportion of providers work in small practices, and in recent months has initiated new programs like <a href="http://nhindirect.org">NHIN Direct</a> that are focused on enabling health information exchange by small or solo practices. It's certainly fair to say that a small practice may not have the same resources to support an EHR implementation that larger practices might (not just money, but IT staff, technical support, etc.), but the EHR incentives available to eligible providers can be applied to any certified EHR system or module, and there will almost certainly be certified products in the market that are suitable for small providers.
The certification final rulling is mostly focused on the application meeting the capabilities that are required for meaningful use. If you look at what the certification requires from a vendor stand point and how it would affect the solo or the large hospital, all the requirements seem to be relevant reguardless of size. Example:
Wave 1 of the published certification tests focuses on things such as:
maintain up to date problem list
maintain up to date medication list
maintain up to date active medication allergy list
Record and chart vital signs
Computerize Order Entry.
Ofcourse, there is the part for meaningful use, which does require the healthcare professional to use the system and capture specific peices of information based on the specialty.
I can see how vendors will have additional costs to worry about (I wrote a post about the process here <a href="http://tiny.cc/m9dlp">Blog post here</a> ), which would mean higher licensing costs for practices, but the requirements seem to focus more on capture data and tracking specific things electronicly.