We apologize for the delay in responding to this issue. We were able to confirm with CMS that CMS submission systems will accept null values the codes for value sets that are negated in the 2015 annual update, which corresponds to the 2016 Performance/Reporting period for all datatypes with the exception of "Device, Not Done". This is due to a standards misalignment issue in the Clinical Document Architecture which will be corrected at a future date. For "Device, Not Done" guidance please refer to the CMS QRDA Implementation Guide.