The R4 implementations of MedicationRequest Reads and Searches[1], DocumentReference Reads and Searches[2], Binary Reads[3], Practitioner Writes[4] and Practitioner.identifier search[5] are now available.
Please take a look at our documentation on fhir.cerner.com and our server release notes[6] if you have any questions about consuming any of the new functionality.
[1] https://fhir.cerner.com/millennium/r4/medications/medication-request/
[2] https://fhir.cerner.com/millennium/r4/documents/document-reference/
[3] https://fhir.cerner.com/millennium/r4/other/binary/
[4] https://fhir.cerner.com/millennium/r4/individuals/practitioner/#create
[5] https://fhir.cerner.com/millennium/r4/individuals/practitioner/#parameters
[6] https://wiki.cerner.com/display/OpenDevRN/Cerner+Ignite+APIs+for+Millennium