diff --git a/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/CovariateCounter.java b/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/CovariateCounter.java
index da9ea62de..3d9214bc0 100755
--- a/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/CovariateCounter.java
+++ b/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/CovariateCounter.java
@@ -2,6 +2,7 @@ package org.broadinstitute.sting.gatk.walkers.recalibration;
 
 import net.sf.samtools.SAMRecord;
 import org.broadinstitute.sting.utils.BaseUtils;
+import org.apache.log4j.Logger;
 
 import javax.management.RuntimeErrorException;
 import java.util.*;
@@ -9,19 +10,27 @@ import java.util.*;
 public class CovariateCounter {
     private boolean collapsePos = false;
     private boolean collapseDinuc = false;
+    private boolean assumeFaultyHeader = false;
 
     private HashMap<String, RecalDataManager> data = new HashMap<String, RecalDataManager>();
 
-    public CovariateCounter( Set<String> readGroups, boolean collapsePos, boolean collapseDinuc ) {
+    protected static Logger logger = Logger.getLogger(CovariateCounter.class);
+
+    public CovariateCounter( Set<String> readGroups, boolean collapsePos, boolean collapseDinuc, boolean assumeFaultyHeader ) {
         this.collapsePos = collapsePos;
         this.collapseDinuc = collapseDinuc;
+        this.assumeFaultyHeader = assumeFaultyHeader;
 
         for (String readGroup : readGroups ) {
-            RecalDataManager manager = new RecalDataManager(readGroup, ! collapsePos, ! collapseDinuc );
+            RecalDataManager manager = makeManager(readGroup);
             data.put(readGroup, manager);
         }
     }
 
+    private RecalDataManager makeManager(final String readGroup) {
+        return new RecalDataManager(readGroup, ! collapsePos, ! collapseDinuc );
+    }
+
     /**
      * Returns the set of readGroup names we are counting covariates for
      * @return
@@ -60,6 +69,17 @@ public class CovariateCounter {
      * @return
      */
     public RecalData getRecalData(String readGroup, int pos, int qual, char prevBase, char base) {
+        if ( ! data.containsKey(readGroup) ) {
+            if ( assumeFaultyHeader ) {
+                logger.info(String.format("Found unexpected read group, but assuming the header was bad, so extending covariates with read group %s", readGroup));
+                RecalDataManager manager = makeManager(readGroup);
+                data.put(readGroup, manager);
+            } else {
+                throw new RuntimeException(String.format("Unexpected read group %s found, there's something wrong with your BAM file's header", readGroup));
+            }
+        }
+        
+
         byte[] cs = {(byte)prevBase, (byte)base};
         String s = new String(cs);
         return data.get(readGroup).expandingGetRecalData(pos, qual, s, true);
diff --git a/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/CovariateCounterWalker.java b/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/CovariateCounterWalker.java
index a2b41b6a2..d6cf705e3 100644
--- a/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/CovariateCounterWalker.java
+++ b/java/src/org/broadinstitute/sting/gatk/walkers/recalibration/CovariateCounterWalker.java
@@ -29,6 +29,9 @@ public class CovariateCounterWalker extends LocusWalker<Integer, PrintStream> {
     public List<String> platforms = Collections.singletonList("*");
     //public List<String> platforms = Collections.singletonList("ILLUMINA");
 
+    @Argument(fullName="assumeFaultyHeader", required=false, doc="")
+    public boolean assumeFaultyHeader = false;
+
     //@Argument(fullName="collapsePos", shortName="collapsePos", required=false, doc="")
     public boolean collapsePos = false;
 
@@ -55,7 +58,7 @@ public class CovariateCounterWalker extends LocusWalker<Integer, PrintStream> {
             readGroups.add(readGroup.getReadGroupId());
         }
 
-        covariateCounter = new CovariateCounter(readGroups, collapsePos, collapseDinuc);
+        covariateCounter = new CovariateCounter(readGroups, collapsePos, collapseDinuc, assumeFaultyHeader);
         logger.info(String.format("Created recalibration data collectors for %d read group(s)", covariateCounter.getNReadGroups()));
     }
 
@@ -88,11 +91,17 @@ public class CovariateCounterWalker extends LocusWalker<Integer, PrintStream> {
                     throw new RuntimeException("Expectedly long read, please increase maxium read len with maxReadLen parameter: " + read.format());
                 }
 
-                SAMReadGroupRecord readGroup = read.getHeader().getReadGroup((String)read.getAttribute("RG"));
+                final String readGroupString = ((String)read.getAttribute("RG"));
+                SAMReadGroupRecord readGroup = read.getHeader().getReadGroup(readGroupString);
+
+                if ( readGroupString == null ) {
+                    throw new RuntimeException("No read group annotation found for read " + read.format());
+                }
+
                 if ((read.getMappingQuality() >= MIN_MAPPING_QUALITY && isSupportedReadGroup(readGroup) )) {
                     int offset = offsets.get(i);
                     if ( offset > 0 && offset < (read.getReadLength() - 1) ) { // skip first and last bases because they suck and they don't have a dinuc count
-                        counted_bases += covariateCounter.updateDataFromRead(readGroup.getReadGroupId(), read, offset, ref);
+                        counted_bases += covariateCounter.updateDataFromRead(readGroupString, read, offset, ref);
                     }
                 }
             }
@@ -115,7 +124,7 @@ public class CovariateCounterWalker extends LocusWalker<Integer, PrintStream> {
     private boolean isSupportedReadGroup( SAMReadGroupRecord readGroup ) {
         for( String platform: platforms ) {
             platform = platform.trim();
-            if( platform.equals("*") ||
+            if( platform.equals("*") || readGroup == null ||
                     readGroup.getAttribute("PL") == null ||
                     readGroup.getAttribute("PL").toString().equalsIgnoreCase(platform) )
                 return true;