Background: As illustrated below the key difference between US Core Clinical Test Result Observation Profile and US Core Imaging Result Observation Profile is the category code: USCDI V2 definitions:   Diagnostic Imaging Tests that result in visual images requiring interpretation by a credentialed professional. Clinical Tests Includes non-imaging and non-laboratory tests performed on a patient that results in structured or unstructured (narrative) findings specific to the patient, such as electrocardiogram (ECG), visual acuity exam, macular exam, or graded exercise testing (GXT), to facilitate the diagnosis and management of conditions. US Core Imaging Result Observation Profile Each Observation must have: a status a category code of ‘imaging’ a  LOINC  code, if available, which tells you what is being measured a patient Each Observation must support: a time indicating when the measurement was taken a result value or a reason why the data is absent* if the result value is a numeric quantity, a standard  UCUM  unit US Core Clinical Test Result Observation Profile Each Observation must have: a status a category code of ‘clinical test'  ** NEW ** based on tracker FHIR-34555 a  LOINC  code, if available, which tells you what is being measured a patient Each Observation must support: a time indicating when the measurement was taken a result value or a reason why the data is absent* if the result value is a numeric quantity, a standard  UCUM  unit A core function of US Core is to define the minimum set of FHIR RESTful interactions for each of the US Core Profiles to access patient data.  By constrained the Observation category element and supporting searching using the combination of the  patient  and  category  search parameters, it supports the ability for US Core Clients to search for a patients Diagnostic Imaging report or Clinical Test data.  However, the profile does not limit having multiple categories such as procedures and so both searches can yield the same data.  The business rules for how systems assign one or more categories to an observation are out of scope.   Reasoning: We agree that these constraints on category may be problematic, but also are an important element for searching for patient data based on these contexts.  Furthermore they do not preclude using both categories to describe tests that are both clinical tests and diagnostic images.  The decision how and what to categorize as a procedure or imaging observation is implementation or implementation community specific. Proposed Changes: Will add text to alert reader to the shortcomings of category based searches.  The text below is a suggestion but Eric will make appropriate changes to ensure readability. The  category concept enables API consumers  to understand what  data has been specifically categorized as such by the responder.  However, consumers should understand what specific  data is needed for their use case, and not rely on responder categorization. Alternatively, clients may find it more efficient to query based on a specific code or set of codes or request all of a patient’s resources for a particular type and filter by code(s) to access items of interest.