CMS considers these two separate, but related issues.
Meaningful use: Any eligible professional demonstrating meaningful use must have at least 50% of their patient encounters during the EHR reporting period at a practice/location or practices/locations equipped with certified EHR technology capable of meeting all of the meaningful use objectives. Therefore, States should collect information on meaningful users' practice locations in order to validate this requirement in an audit.
Patient volume: Eligible professionals may choose one (or more) clinical sites of practice in order to calculate their patient volume. This calculation does not need to be across all of an eligible professional's sites of practice. However, at least one of the locations where the eligible professional is adopting or meaningfully using certified EHR technology should be included in the patient volume. In other words, if an eligible professional practices in two locations, one with certified EHR technology and one without, the eligible professional should include the patient volume at least at the site that includes the certified EHR technology. When making an individual patient volume calculation (i.e., not using the group/clinic proxy option), a professional may calculate across all practice sites, or just at the one site. For more information on applying the group/clinic proxy option, see FAQ #10362 or click here.
For more information about the Medicare and Medicaid EHR Incentive Program, please visit http://www.cms.gov/EHRIncentivePrograms.