diff --git a/zymoTransmit.py b/zymoTransmit.py
index 809c4ba..2b3ceff 100644
--- a/zymoTransmit.py
+++ b/zymoTransmit.py
@@ -133,6 +133,11 @@ def makeHL7Codes(resultList:typing.List[zymoTransmitSupport.inputOutput.resultRe
         currentSet.append(zymoTransmitSupport.hl7Encoder.encoders.makeSPMLine(result))
         if result.note:
             currentSet.append(zymoTransmitSupport.hl7Encoder.encoders.makeNTELine(result))
+        if not result.okToTransmit:
+            print("Skipping preparation of %s:%s for the following reasons:" %(result.patientID, result.specimenID))
+            for reason in result.reasonsNotToTransmit:
+                print("\t%s" %reason)
+            del hl7Sets[(patientID, specimenID)]
     return hl7Sets
 
 
diff --git a/zymoTransmitSupport/config.py b/zymoTransmitSupport/config.py
index db28617..2d871b8 100644
--- a/zymoTransmitSupport/config.py
+++ b/zymoTransmitSupport/config.py
@@ -138,7 +138,7 @@ class Facility:
             idType = "CLIA"
 
 class ResultTerms:
-    positiveResultTerms = ["POSITIVE", "DETECTED", "POS"]
-    indeterminateResultTerms = ["INDETERMINATE", "N/A", "UNKNOWN", "INCONCLUSIVE", "INVALID"]
-    negativeResultTerms = ["ND", "NEG", "NEGATIVE", "NOT DETECTED"]
-    unsatisfactorySpecimenResultTerms = ["UNSATISFACTORY SPECIMEN", "SPECIMEN UNSATISFACTORY", "UNSATISFACTORY"]
\ No newline at end of file
+    positiveResultTerms = ["POSITIVE", "DETECTED", "POS", "260373001", "SARS-COV-2 NUCLEIC ACID DETECTED BY BDMAX", "POSITIVE SARS-COV-2", "DETECT", "REACTIVE", "DETECT", "2019-NCOV NUCLEIC ACID DETECTED BY GENEXPERT"]
+    indeterminateResultTerms = ["INDETERMINATE", "N/A", "UNKNOWN", "INCONCLUSIVE", "INVALID", "419984006"]
+    negativeResultTerms = ["ND", "NEG", "NEGATIVE", "NOT DETECTED", "260415000", "NOTDET", "NONE DETECTED", "NONREACTIVE", "NON-REACTIVE", "NOT_DETECTED", "COVID-19 (SARS-COV-2) RNA: NOT DETECTED"]
+    unsatisfactorySpecimenResultTerms = ["UNSATISFACTORY SPECIMEN", "SPECIMEN UNSATISFACTORY", "UNSATISFACTORY", "125154007"]
\ No newline at end of file
diff --git a/zymoTransmitSupport/hl7Encoder/encoders.py b/zymoTransmitSupport/hl7Encoder/encoders.py
index a497b32..8e2a347 100644
--- a/zymoTransmitSupport/hl7Encoder/encoders.py
+++ b/zymoTransmitSupport/hl7Encoder/encoders.py
@@ -200,7 +200,9 @@ def makeOBRLine(result:inputOutput.resultReader.TestResult):
 def makeOBXLine(result:inputOutput.resultReader.TestResult):
     def makeObservationValueAndAbnormalityObjects(resultString:str):
         resultStringUpper = resultString.upper()
-        if resultStringUpper in config.ResultTerms.indeterminateResultTerms:
+        if "NOT DETECTED" in resultStringUpper:
+            resultTerm = "negative"
+        elif resultStringUpper in config.ResultTerms.indeterminateResultTerms:
             resultTerm = "indeterminate"
         elif resultStringUpper in config.ResultTerms.positiveResultTerms:
             resultTerm = "detected"
@@ -209,7 +211,10 @@ def makeObservationValueAndAbnormalityObjects(resultString:str):
         elif resultStringUpper in config.ResultTerms.unsatisfactorySpecimenResultTerms:
             resultTerm = "unsatisfactory"
         else:
-            raise ValueError("Unable to classify result '%s'. Preferred terms are: detected, indeterminate, negative, and unsatisfactory specimen." %resultString)
+            print("Unable to classify result '%s' for patient %s specimen %s. Preferred terms are: detected, indeterminate, negative, and unsatisfactory specimen." %(resultString, result.patientID, result.specimenID))
+            resultTerm = ""
+            result.okToTransmit = False
+            result.reasonsNotToTransmit.append("Failed to interpret result value")
         return (observedResults.getObservationValue(resultTerm),
                 observedResults.getAbnormalityObject(resultTerm))
 
diff --git a/zymoTransmitSupport/hl7Encoder/observedResults.py b/zymoTransmitSupport/hl7Encoder/observedResults.py
index e12c5fc..33fadfa 100644
--- a/zymoTransmitSupport/hl7Encoder/observedResults.py
+++ b/zymoTransmitSupport/hl7Encoder/observedResults.py
@@ -32,7 +32,7 @@ def getObservationValue(result:str):
     :param result: String describing the result. Must be in ["detected", "indeterminate", "negative"]
     :return: An appropriate result as a generics.SystemCode object
     '''
-    validResults = ["detected", "indeterminate", "negative", "unsatisfactory"]
+    validResults = ["detected", "indeterminate", "negative", "unsatisfactory", ""]
     if not result in validResults:
         raise ValueError("Result type must be in: " %validResults)
     if result == "detected":
@@ -43,6 +43,8 @@ def getObservationValue(result:str):
         return generics.SystemCode(code="260415000", text="Not detected", coding="SNOMED", codingSystemDateOrVersion="2.7")
     elif result == "unsatisfactory":
         return generics.SystemCode(code="125154007", text="Specimen unsatisfactory", coding="SNOMED", codingSystemDateOrVersion="2.7")
+    elif result == "":
+        return ""
     else:
         raise RuntimeError("This code should be unreachable if result validations is working properly and how we got here needs to be investigated")
 
@@ -61,7 +63,7 @@ def getAbnormalityObject(result:str):
     :param result: String describing the result. Must be in ["detected", "indeterminate", "negative"]
     :return: An appropriate result as a generics.SystemCode object
     '''
-    validResults = ["detected", "indeterminate", "negative", "unsatisfactory"]
+    validResults = ["detected", "indeterminate", "negative", "unsatisfactory", ""]
     if not result in validResults:
         raise ValueError("Result type must be in: " %validResults)
     if result == "detected":
@@ -72,6 +74,8 @@ def getAbnormalityObject(result:str):
         return generics.SystemCode(code="260415000", text="Not detected", coding="SNOMED", codingSystemDateOrVersion="2.7")
     elif result == "unsatisfactory":
         return generics.SystemCode(code="125154007", text="Specimen unsatisfactory", coding="SNOMED", codingSystemDateOrVersion="2.7")
+    elif result == "":
+        return ""
     else:
         raise RuntimeError("This code should be unreachable if result validations is working properly and how we got here needs to be investigated")
 
diff --git a/zymoTransmitSupport/inputOutput/resultReader.py b/zymoTransmitSupport/inputOutput/resultReader.py
index 52c311c..ee964f2 100644
--- a/zymoTransmitSupport/inputOutput/resultReader.py
+++ b/zymoTransmitSupport/inputOutput/resultReader.py
@@ -58,6 +58,8 @@ def __init__(self, rawLine: [str, collections.Iterable], delimiter: str = "\t"):
         self.analysisDateTime = self.processDateAndTime(analysisDate, analysisTime)
         self.reportedDateTime = self.processDateAndTime(reportedDate, reportedTime)
         self.auxiliaryData = {}
+        self.okToTransmit = True
+        self.reasonsNotToTransmit = []
 
     def processRawLine(self, delimiter):
         rawLine = self.rawLine.strip()