diff --git a/avocado-core/src/main/scala/org/bdgenomics/avocado/genotyping/posAlleleStats.scala b/avocado-core/src/main/scala/org/bdgenomics/avocado/genotyping/posAlleleStats.scala
new file mode 100644
index 00000000..39c926ba
--- /dev/null
+++ b/avocado-core/src/main/scala/org/bdgenomics/avocado/genotyping/posAlleleStats.scala
@@ -0,0 +1,188 @@
+package org.bdgenomics.avocado.genotyping
+
+import java.io
+
+import org.apache.spark.rdd.RDD
+import org.apache.spark.sql.SQLContext
+import org.bdgenomics.adam.models.ReferencePosition
+import org.bdgenomics.adam.rdd.read.AlignmentRecordRDD
+import org.bdgenomics.adam.rdd.variant.VariantRDD
+import org.bdgenomics.avocado.Timers._
+import org.bdgenomics.avocado.models.{ Clipped, Deletion, Insertion, Match, ObservationOperator }
+import org.bdgenomics.formats.avro.{ AlignmentRecord, Variant }
+import org.bdgenomics.utils.misc.Logging
+
+import scala.annotation.tailrec
+import scala.collection.mutable
+
+/**
+ * Counts Bases (A C G T) as well as ins / del at each position covered by at least one read in the input alignment file
+ */
+object PosAlleleStats extends Serializable with Logging {
+
+  case class AlleleCounts(var A: Int, var C: Int, var G: Int, var T: Int, var N: Int, var ins: Int, var del: Int)
+
+  def runPosAlleleStats(alignmentRecordRDD: AlignmentRecordRDD, phredThreshold: Int = 33): RDD[(org.bdgenomics.adam.models.ReferencePosition, org.bdgenomics.avocado.genotyping.PosAlleleStats.AlleleCounts)] = {
+
+    def posAlleleStatsMapPartitions(in: Iterator[AlignmentRecord]): Iterator[(ReferencePosition, AlleleCounts)] = {
+
+      // hash of allele counters per genomics position
+      val x: mutable.Map[ReferencePosition, AlleleCounts] = new scala.collection.mutable.HashMap[org.bdgenomics.adam.models.ReferencePosition, AlleleCounts]
+
+      in.foreach(read => {
+        if (!read.getReadMapped) {
+          Iterable.empty
+        } else {
+          // extract the alignment blocks from the read
+          val ops = try {
+            ObservationOperator.extractAlignmentOperators(read)
+          } catch {
+            case t: Throwable => {
+              log.warn("Extracting alignment operators from %s failed with %s.".format(
+                read.getReadName, t))
+              Iterable.empty
+            }
+          }
+
+          // where are we on the reference and in the read?
+          var pos = read.getStart.toInt
+          var idx = 0
+
+          // get the read sequence, contig, etc
+          val sequence: String = read.getSequence
+          val qual: String = read.getQual
+
+          println(sequence)
+          println(qual)
+
+          val contigName = read.getContigName
+
+          // advance to the first alignment match
+          @tailrec def fastForward(
+            iter: BufferedIterator[ObservationOperator]): Iterator[ObservationOperator] = {
+
+            if (!iter.hasNext) {
+              Iterator()
+            } else {
+              val stop = iter.head match {
+                case Clipped(_, false) => false
+                case Clipped(length, true) => {
+                  idx += length
+                  false
+                }
+                case Insertion(length) => {
+                  idx += length
+                  false
+                }
+                case Deletion(ref) => {
+                  pos += ref.length
+                  false
+                }
+                case Match(_, _) => {
+                  true
+                }
+              }
+
+              if (stop) {
+                iter.toIterator
+              } else {
+                // pop from the iterator and recurse
+                iter.next
+                fastForward(iter)
+              }
+            }
+          }
+
+          val opsIter = fastForward(ops.toIterator.buffered)
+
+          def incrementBaseCount(i: Char, pos: ReferencePosition, qual: Int): Unit = {
+
+            if (!x.isDefinedAt(pos)) {
+              x(pos) = AlleleCounts(0, 0, 0, 0, 0, 0, 0)
+            }
+
+            if (qual >= phredThreshold) {
+              if (i.toUpper == 'A') {
+                x(pos).A += 1
+              } else if (i.toUpper == 'C') {
+                x(pos).C += 1
+              } else if (i.toUpper == 'G') {
+                x(pos).G += 1
+              } else if (i.toUpper == 'T') {
+                x(pos).T += 1
+              }
+            } else {
+              x(pos).N += 1
+            }
+          }
+
+          @tailrec def recordAlleles(iter: Iterator[ObservationOperator],
+                                     lastRef: String = ""): Unit = {
+
+            if (!iter.hasNext) {
+              None
+            } else {
+              // pop from the iterator
+              val obs = iter.next
+              // update the list and position and advance
+              val (nextRef) = obs match {
+                case Clipped(_, _) => {
+                  (lastRef)
+                }
+                case Match(length, optRef) => {
+                  val kv = optRef.fold({
+                    (0 until length).foreach(i => {
+                      incrementBaseCount(sequence(idx + i), ReferencePosition(contigName, pos + i), qual(idx + i).toInt - 33)
+                      //println("test qual i:" + i + " idx:" + idx + " alt: " + qual(i).toString + " fixed_alt: " + qual(i + idx) + " qual: " + (qual(idx + i).toInt - 33))
+                    })
+                    sequence(idx + length - 1).toString
+                  })((ref: String) => {
+                    (0 until length).foreach(i => {
+                      //println("test qual i:" + i + " idx:" + idx + " ref:" + ref(i).toString() + " alt: " + qual(i).toString + " fixed_alt: " + qual(i + idx) + " qual: " + (qual(idx + i).toInt - 33))
+                      incrementBaseCount(sequence(idx + i), ReferencePosition(contigName, pos + i), qual(idx + i).toInt - 33)
+                    })
+                    ref.last.toString
+                  })
+                  pos += length
+                  idx += length
+                  kv
+                }
+                case Insertion(length) => {
+                  val insQuals = qual.substring(idx - 1, idx + length).map(_.toInt - 33).sum / length
+                  if (insQuals >= phredThreshold) { x(ReferencePosition(contigName, pos - 1)).ins += 1 }
+                  idx += length
+                  (lastRef)
+                }
+                case Deletion(ref) => {
+                  val delLength = ref.size
+                  if (qual(idx - 1).toInt - 33 >= phredThreshold) { x(ReferencePosition(contigName, pos)).del += 1 }
+                  pos += delLength
+                  (ref.last.toString)
+                }
+              }
+
+              // recurse
+              recordAlleles(iter, nextRef)
+            }
+          }
+
+          recordAlleles(opsIter)
+        }
+
+      })
+
+      x.toIterator
+    }
+
+    alignmentRecordRDD.rdd.mapPartitions(posAlleleStatsMapPartitions)
+      .reduceByKey((x, y) => AlleleCounts(x.A + y.A,
+        x.C + y.C,
+        x.G + y.G,
+        x.T + y.T,
+        x.N + y.N,
+        x.ins + y.ins,
+        x.del + y.del))
+  }
+
+}
+