diff --git a/sstruct_mv/sstruct_matrix.c b/sstruct_mv/sstruct_matrix.c
index 220ec5f18..8c0a16ad7 100644
--- a/sstruct_mv/sstruct_matrix.c
+++ b/sstruct_mv/sstruct_matrix.c
@@ -290,6 +290,8 @@ hypre_SStructPMatrixSetValues( hypre_SStructPMatrix *pmatrix,
    int                  *smap    = hypre_SStructPMatrixSMap(pmatrix, var);
    int                  *vars    = hypre_SStructStencilVars(stencil);
    hypre_StructMatrix   *smatrix;
+   hypre_BoxArray       *grid_boxes;
+   hypre_Box            *box;
    int                  *sentries;
    int                   i;
 
@@ -305,13 +307,12 @@ hypre_SStructPMatrixSetValues( hypre_SStructPMatrix *pmatrix,
    hypre_StructMatrixSetValues(smatrix, index, nentries, sentries, values,
                                action, -1, 0);
 
-   /* set values outside the grid in ghost zones (for AddTo and Get) */
+   /* set (AddTo/Get) or clear (Set) values outside the grid in ghost zones */
    if (action != 0)
    {
+      /* AddTo/Get */
       hypre_SStructPGrid  *pgrid = hypre_SStructPMatrixPGrid(pmatrix);
       hypre_Index          varoffset;
-      hypre_BoxArray      *grid_boxes;
-      hypre_Box           *box;
       int                  done = 0;
 
       grid_boxes = hypre_StructGridBoxes(hypre_StructMatrixGrid(smatrix));
@@ -358,6 +359,25 @@ hypre_SStructPMatrixSetValues( hypre_SStructPMatrix *pmatrix,
          }
       }
    }
+   else
+   {
+      /* Set */
+      grid_boxes = hypre_StructGridBoxes(hypre_StructMatrixGrid(smatrix));
+
+      hypre_ForBoxI(i, grid_boxes)
+      {
+         box = hypre_BoxArrayBox(grid_boxes, i);
+         if ((hypre_IndexX(index) < hypre_BoxIMinX(box)) ||
+             (hypre_IndexX(index) > hypre_BoxIMaxX(box)) ||
+             (hypre_IndexY(index) < hypre_BoxIMinY(box)) ||
+             (hypre_IndexY(index) > hypre_BoxIMaxY(box)) ||
+             (hypre_IndexZ(index) < hypre_BoxIMinZ(box)) ||
+             (hypre_IndexZ(index) > hypre_BoxIMaxZ(box))   )
+         {
+            hypre_StructMatrixClearValues(smatrix, index, nentries, sentries, i, 1);
+         }
+      }
+   }
 
    return hypre_error_flag;
 }
@@ -383,10 +403,11 @@ hypre_SStructPMatrixSetBoxValues( hypre_SStructPMatrix *pmatrix,
    int                  *smap    = hypre_SStructPMatrixSMap(pmatrix, var);
    int                  *vars    = hypre_SStructStencilVars(stencil);
    hypre_StructMatrix   *smatrix;
+   hypre_BoxArray       *grid_boxes;
    hypre_Box            *box;
    hypre_Box            *value_box;
    int                  *sentries;
-   int                   i;
+   int                   i, j;
 
    smatrix = hypre_SStructPMatrixSMatrix(pmatrix, var, vars[entries[0]]);
 
@@ -405,15 +426,14 @@ hypre_SStructPMatrixSetBoxValues( hypre_SStructPMatrix *pmatrix,
    hypre_StructMatrixSetBoxValues(smatrix, box, value_box, nentries, sentries,
                                   values, action, -1, 0);
 
-   /* set values outside the grid in ghost zones (for AddTo and Get) */
+   /* set (AddTo/Get) or clear (Set) values outside the grid in ghost zones */
    if (action != 0)
    {
+      /* AddTo/Get */
       hypre_SStructPGrid  *pgrid = hypre_SStructPMatrixPGrid(pmatrix);
       hypre_Index          varoffset;
-      hypre_BoxArray      *grid_boxes;
       hypre_BoxArray      *left_boxes, *done_boxes, *temp_boxes;
       hypre_Box           *left_box, *done_box, *int_box;
-      int                  j;
 
       hypre_SStructVariableGetOffset(hypre_SStructPGridVarType(pgrid, var),
                                      hypre_SStructPGridNDim(pgrid), varoffset);
@@ -458,6 +478,30 @@ hypre_SStructPMatrixSetBoxValues( hypre_SStructPMatrix *pmatrix,
       hypre_BoxArrayDestroy(done_boxes);
       hypre_BoxArrayDestroy(temp_boxes);
    }
+   else
+   {
+      /* Set */
+      hypre_BoxArray  *diff_boxes;
+      hypre_Box       *grid_box, *diff_box;
+
+      grid_boxes = hypre_StructGridBoxes(hypre_StructMatrixGrid(smatrix));
+      diff_boxes = hypre_BoxArrayCreate(0);
+
+      hypre_ForBoxI(i, grid_boxes)
+      {
+         grid_box = hypre_BoxArrayBox(grid_boxes, i);
+         hypre_BoxArraySetSize(diff_boxes, 0);
+         hypre_SubtractBoxes(box, grid_box, diff_boxes);
+
+         hypre_ForBoxI(j, diff_boxes)
+         {
+            diff_box = hypre_BoxArrayBox(diff_boxes, j);
+            hypre_StructMatrixClearBoxValues(smatrix, diff_box, nentries, sentries,
+                                             i, 1);
+         }
+      }
+      hypre_BoxArrayDestroy(diff_boxes);
+   }
 
    hypre_BoxDestroy(box);
 
diff --git a/sstruct_mv/sstruct_vector.c b/sstruct_mv/sstruct_vector.c
index ff91fd1b9..433d049ed 100644
--- a/sstruct_mv/sstruct_vector.c
+++ b/sstruct_mv/sstruct_vector.c
@@ -179,19 +179,20 @@ hypre_SStructPVectorSetValues( hypre_SStructPVector *pvector,
                                int                   action )
 {
    hypre_StructVector *svector = hypre_SStructPVectorSVector(pvector, var);
+   hypre_BoxArray     *grid_boxes;
+   hypre_Box          *box;
+   int                 i;
 
    /* set values inside the grid */
    hypre_StructVectorSetValues(svector, index, value, action, -1, 0);
 
-   /* set values outside the grid in ghost zones (for AddTo and Get) */
+   /* set (AddTo/Get) or clear (Set) values outside the grid in ghost zones */
    if (action != 0)
    {
-      hypre_SStructPGrid  *pgrid = hypre_SStructPVectorPGrid(pvector);
-      hypre_Index          varoffset;
-      hypre_BoxArray      *grid_boxes;
-      hypre_Box           *box;
-      int                  i;
-      int                  done = 0;
+      /* AddTo/Get */
+      hypre_SStructPGrid *pgrid = hypre_SStructPVectorPGrid(pvector);
+      hypre_Index         varoffset;
+      int                 done = 0;
 
       grid_boxes = hypre_StructGridBoxes(hypre_StructVectorGrid(svector));
 
@@ -236,6 +237,25 @@ hypre_SStructPVectorSetValues( hypre_SStructPVector *pvector,
          }
       }
    }
+   else
+   {
+      /* Set */
+      grid_boxes = hypre_StructGridBoxes(hypre_StructVectorGrid(svector));
+
+      hypre_ForBoxI(i, grid_boxes)
+      {
+         box = hypre_BoxArrayBox(grid_boxes, i);
+         if ((hypre_IndexX(index) < hypre_BoxIMinX(box)) ||
+             (hypre_IndexX(index) > hypre_BoxIMaxX(box)) ||
+             (hypre_IndexY(index) < hypre_BoxIMinY(box)) ||
+             (hypre_IndexY(index) > hypre_BoxIMaxY(box)) ||
+             (hypre_IndexZ(index) < hypre_BoxIMinZ(box)) ||
+             (hypre_IndexZ(index) > hypre_BoxIMaxZ(box))   )
+         {
+            hypre_StructVectorClearValues(svector, index, i, 1);
+         }
+      }
+   }
 
    return hypre_error_flag;
 }
@@ -255,8 +275,10 @@ hypre_SStructPVectorSetBoxValues( hypre_SStructPVector *pvector,
                                   int                   action )
 {
    hypre_StructVector *svector = hypre_SStructPVectorSVector(pvector, var);
+   hypre_BoxArray     *grid_boxes;
    hypre_Box          *box;
    hypre_Box          *value_box;
+   int                 i, j;
 
    box = hypre_BoxCreate();
    hypre_CopyIndex(ilower, hypre_BoxIMin(box));
@@ -266,15 +288,14 @@ hypre_SStructPVectorSetBoxValues( hypre_SStructPVector *pvector,
    /* set values inside the grid */
    hypre_StructVectorSetBoxValues(svector, box, value_box, values, action, -1, 0);
 
-   /* set values outside the grid in ghost zones (for AddTo and Get) */
+   /* set (AddTo/Get) or clear (Set) values outside the grid in ghost zones */
    if (action != 0)
    {
+      /* AddTo/Get */
       hypre_SStructPGrid  *pgrid = hypre_SStructPVectorPGrid(pvector);
       hypre_Index          varoffset;
-      hypre_BoxArray      *grid_boxes;
       hypre_BoxArray      *left_boxes, *done_boxes, *temp_boxes;
       hypre_Box           *left_box, *done_box, *int_box;
-      int                  i, j;
 
       hypre_SStructVariableGetOffset(hypre_SStructPGridVarType(pgrid, var),
                                      hypre_SStructPGridNDim(pgrid), varoffset);
@@ -318,6 +339,29 @@ hypre_SStructPVectorSetBoxValues( hypre_SStructPVector *pvector,
       hypre_BoxArrayDestroy(done_boxes);
       hypre_BoxArrayDestroy(temp_boxes);
    }
+   else
+   {
+      /* Set */
+      hypre_BoxArray  *diff_boxes;
+      hypre_Box       *grid_box, *diff_box;
+
+      grid_boxes = hypre_StructGridBoxes(hypre_StructVectorGrid(svector));
+      diff_boxes = hypre_BoxArrayCreate(0);
+
+      hypre_ForBoxI(i, grid_boxes)
+      {
+         grid_box = hypre_BoxArrayBox(grid_boxes, i);
+         hypre_BoxArraySetSize(diff_boxes, 0);
+         hypre_SubtractBoxes(box, grid_box, diff_boxes);
+
+         hypre_ForBoxI(j, diff_boxes)
+         {
+            diff_box = hypre_BoxArrayBox(diff_boxes, j);
+            hypre_StructVectorClearBoxValues(svector, diff_box, i, 1);
+         }
+      }
+      hypre_BoxArrayDestroy(diff_boxes);
+   }
 
    hypre_BoxDestroy(box);
 
diff --git a/struct_mv/_hypre_struct_mv.h b/struct_mv/_hypre_struct_mv.h
index 5fb6031d2..b98df9bc5 100644
--- a/struct_mv/_hypre_struct_mv.h
+++ b/struct_mv/_hypre_struct_mv.h
@@ -2349,6 +2349,8 @@ int hypre_StructMatrixInitialize ( hypre_StructMatrix *matrix );
 int hypre_StructMatrixSetValues ( hypre_StructMatrix *matrix , hypre_Index grid_index , int num_stencil_indices , int *stencil_indices , double *values , int action , int boxnum , int outside );
 int hypre_StructMatrixSetBoxValues ( hypre_StructMatrix *matrix , hypre_Box *set_box , hypre_Box *value_box , int num_stencil_indices , int *stencil_indices , double *values , int action , int boxnum , int outside );
 int hypre_StructMatrixSetConstantValues ( hypre_StructMatrix *matrix , int num_stencil_indices , int *stencil_indices , double *values , int action );
+int hypre_StructMatrixClearValues ( hypre_StructMatrix *matrix , hypre_Index grid_index , int num_stencil_indices , int *stencil_indices , int boxnum , int outside );
+int hypre_StructMatrixClearBoxValues ( hypre_StructMatrix *matrix , hypre_Box *clear_box , int num_stencil_indices , int *stencil_indices , int boxnum , int outside );
 int hypre_StructMatrixAssemble ( hypre_StructMatrix *matrix );
 int hypre_StructMatrixSetNumGhost ( hypre_StructMatrix *matrix , int *num_ghost );
 int hypre_StructMatrixSetConstantCoefficient ( hypre_StructMatrix *matrix , int constant_coefficient );
@@ -2393,6 +2395,8 @@ int hypre_StructVectorInitializeData ( hypre_StructVector *vector , double *data
 int hypre_StructVectorInitialize ( hypre_StructVector *vector );
 int hypre_StructVectorSetValues ( hypre_StructVector *vector , hypre_Index grid_index , double *values , int action , int boxnum , int outside );
 int hypre_StructVectorSetBoxValues ( hypre_StructVector *vector , hypre_Box *set_box , hypre_Box *value_box , double *values , int action , int boxnum , int outside );
+int hypre_StructVectorClearValues ( hypre_StructVector *vector , hypre_Index grid_index , int boxnum , int outside );
+int hypre_StructVectorClearBoxValues ( hypre_StructVector *vector , hypre_Box *clear_box , int boxnum , int outside );
 int hypre_StructVectorSetNumGhost ( hypre_StructVector *vector , int *num_ghost );
 int hypre_StructVectorAssemble ( hypre_StructVector *vector );
 int hypre_StructVectorCopy ( hypre_StructVector *x , hypre_StructVector *y );
diff --git a/struct_mv/struct_matrix.c b/struct_mv/struct_matrix.c
index 066bcaf18..07d3d1c22 100644
--- a/struct_mv/struct_matrix.c
+++ b/struct_mv/struct_matrix.c
@@ -1057,6 +1057,177 @@ hypre_StructMatrixSetConstantValues( hypre_StructMatrix *matrix,
    return hypre_error_flag;
 }
 
+/*--------------------------------------------------------------------------
+ * (outside > 0): clear values possibly outside of the grid extents
+ * (outside = 0): clear values only inside the grid extents
+ *--------------------------------------------------------------------------*/
+
+int 
+hypre_StructMatrixClearValues( hypre_StructMatrix *matrix,
+                               hypre_Index         grid_index,
+                               int                 num_stencil_indices,
+                               int                *stencil_indices,
+                               int                 boxnum,
+                               int                 outside )
+{
+   hypre_BoxArray      *grid_boxes;
+   hypre_Box           *grid_box;
+
+   double              *matp;
+
+   int                  i, s, istart, istop;
+ 
+   /*-----------------------------------------------------------------------
+    * Initialize some things
+    *-----------------------------------------------------------------------*/
+
+   if (outside > 0)
+   {
+      grid_boxes = hypre_StructMatrixDataSpace(matrix);
+   }
+   else
+   {
+      grid_boxes = hypre_StructGridBoxes(hypre_StructMatrixGrid(matrix));
+   }
+
+   if (boxnum < 0)
+   {
+      istart = 0;
+      istop  = hypre_BoxArraySize(grid_boxes);
+   }
+   else
+   {
+      istart = boxnum;
+      istop  = istart + 1;
+   }
+
+   /*-----------------------------------------------------------------------
+    * Clear the matrix coefficients
+    *-----------------------------------------------------------------------*/
+
+   for (i = istart; i < istop; i++)
+   {
+      grid_box = hypre_BoxArrayBox(grid_boxes, i);
+
+      if ((hypre_IndexX(grid_index) >= hypre_BoxIMinX(grid_box)) &&
+          (hypre_IndexX(grid_index) <= hypre_BoxIMaxX(grid_box)) &&
+          (hypre_IndexY(grid_index) >= hypre_BoxIMinY(grid_box)) &&
+          (hypre_IndexY(grid_index) <= hypre_BoxIMaxY(grid_box)) &&
+          (hypre_IndexZ(grid_index) >= hypre_BoxIMinZ(grid_box)) &&
+          (hypre_IndexZ(grid_index) <= hypre_BoxIMaxZ(grid_box))   )
+      {
+         for (s = 0; s < num_stencil_indices; s++)
+         {
+            matp = hypre_StructMatrixBoxDataValue(matrix, i,
+                                                  stencil_indices[s],
+                                                  grid_index);
+            *matp = 0.0;
+         }
+      }
+   }
+
+   return hypre_error_flag;
+}
+
+/*--------------------------------------------------------------------------
+ * (outside > 0): clear values possibly outside of the grid extents
+ * (outside = 0): clear values only inside the grid extents
+ *--------------------------------------------------------------------------*/
+
+int 
+hypre_StructMatrixClearBoxValues( hypre_StructMatrix *matrix,
+                                hypre_Box          *clear_box,
+                                int                 num_stencil_indices,
+                                int                *stencil_indices,
+                                int                 boxnum,
+                                int                 outside )
+{
+   hypre_BoxArray      *grid_boxes;
+   hypre_Box           *grid_box;
+   hypre_Box           *int_box;
+                   
+   hypre_BoxArray      *data_space;
+   hypre_Box           *data_box;
+   hypre_IndexRef       data_start;
+   hypre_Index          data_stride;
+   int                  datai;
+   double              *datap;
+                   
+   hypre_Index          loop_size;
+                   
+   int                  i, s, istart, istop;
+   int                  loopi, loopj, loopk;
+
+   /*-----------------------------------------------------------------------
+    * Initialize some things
+    *-----------------------------------------------------------------------*/
+
+   if (outside > 0)
+   {
+      grid_boxes = hypre_StructMatrixDataSpace(matrix);
+   }
+   else
+   {
+      grid_boxes = hypre_StructGridBoxes(hypre_StructMatrixGrid(matrix));
+   }
+   data_space = hypre_StructMatrixDataSpace(matrix);
+
+   if (boxnum < 0)
+   {
+      istart = 0;
+      istop  = hypre_BoxArraySize(grid_boxes);
+   }
+   else
+   {
+      istart = boxnum;
+      istop  = istart + 1;
+   }
+
+   /*-----------------------------------------------------------------------
+    * Clear the matrix coefficients
+    *-----------------------------------------------------------------------*/
+
+   hypre_SetIndex(data_stride, 1, 1, 1);
+
+   int_box = hypre_BoxCreate();
+
+   for (i = istart; i < istop; i++)
+   {
+      grid_box = hypre_BoxArrayBox(grid_boxes, i);
+      data_box = hypre_BoxArrayBox(data_space, i);
+
+      hypre_IntersectBoxes(clear_box, grid_box, int_box);
+
+      /* if there was an intersection */
+      if (int_box)
+      {
+         data_start = hypre_BoxIMin(int_box);
+
+         for (s = 0; s < num_stencil_indices; s++)
+         {
+            datap = hypre_StructMatrixBoxData(matrix, i,
+                                              stencil_indices[s]);
+
+            hypre_BoxGetSize(int_box, loop_size);
+
+            hypre_BoxLoop1Begin(loop_size,
+                                data_box,data_start,data_stride,datai);
+#define HYPRE_BOX_SMP_PRIVATE loopk,loopi,loopj,datai
+#include "hypre_box_smp_forloop.h"
+            hypre_BoxLoop1For(loopi, loopj, loopk, datai)
+            {
+               datap[datai] = 0.0;
+            }
+            hypre_BoxLoop1End(datai);
+         }
+      }
+   }
+
+   hypre_BoxDestroy(int_box);
+
+   return hypre_error_flag;
+}
+
 /*--------------------------------------------------------------------------
  *--------------------------------------------------------------------------*/
 
diff --git a/struct_mv/struct_vector.c b/struct_mv/struct_vector.c
index 95bddaf52..611db2467 100644
--- a/struct_mv/struct_vector.c
+++ b/struct_mv/struct_vector.c
@@ -426,6 +426,156 @@ hypre_StructVectorSetBoxValues( hypre_StructVector *vector,
    return hypre_error_flag;
 }
 
+/*--------------------------------------------------------------------------
+ * (outside > 0): clear values possibly outside of the grid extents
+ * (outside = 0): clear values only inside the grid extents
+ *--------------------------------------------------------------------------*/
+
+int 
+hypre_StructVectorClearValues( hypre_StructVector *vector,
+                               hypre_Index         grid_index,
+                               int                 boxnum,
+                               int                 outside    )
+{
+   hypre_BoxArray     *grid_boxes;
+   hypre_Box          *grid_box;
+
+   double             *vecp;
+
+   int                 i, istart, istop;
+
+   if (outside > 0)
+   {
+      grid_boxes = hypre_StructVectorDataSpace(vector);
+   }
+   else
+   {
+      grid_boxes = hypre_StructGridBoxes(hypre_StructVectorGrid(vector));
+   }
+
+   if (boxnum < 0)
+   {
+      istart = 0;
+      istop  = hypre_BoxArraySize(grid_boxes);
+   }
+   else
+   {
+      istart = boxnum;
+      istop  = istart + 1;
+   }
+
+   for (i = istart; i < istop; i++)
+   {
+      grid_box = hypre_BoxArrayBox(grid_boxes, i);
+
+      if ((hypre_IndexX(grid_index) >= hypre_BoxIMinX(grid_box)) &&
+          (hypre_IndexX(grid_index) <= hypre_BoxIMaxX(grid_box)) &&
+          (hypre_IndexY(grid_index) >= hypre_BoxIMinY(grid_box)) &&
+          (hypre_IndexY(grid_index) <= hypre_BoxIMaxY(grid_box)) &&
+          (hypre_IndexZ(grid_index) >= hypre_BoxIMinZ(grid_box)) &&
+          (hypre_IndexZ(grid_index) <= hypre_BoxIMaxZ(grid_box))   )
+      {
+         vecp = hypre_StructVectorBoxDataValue(vector, i, grid_index);
+         *vecp = 0.0;
+      }
+   }
+
+   return hypre_error_flag;
+}
+
+/*--------------------------------------------------------------------------
+ * (outside > 0): clear values possibly outside of the grid extents
+ * (outside = 0): clear values only inside the grid extents
+ *--------------------------------------------------------------------------*/
+
+int 
+hypre_StructVectorClearBoxValues( hypre_StructVector *vector,
+                                  hypre_Box          *clear_box,
+                                  int                 boxnum,
+                                  int                 outside )
+{
+   hypre_BoxArray     *grid_boxes;
+   hypre_Box          *grid_box;
+   hypre_Box          *int_box;
+
+   hypre_BoxArray     *data_space;
+   hypre_Box          *data_box;
+   hypre_IndexRef      data_start;
+   hypre_Index         data_stride;
+   int                 datai;
+   double             *datap;
+
+   hypre_Index         loop_size;
+
+   int                 i, istart, istop;
+   int                 loopi, loopj, loopk;
+
+   /*-----------------------------------------------------------------------
+    * Initialize some things
+    *-----------------------------------------------------------------------*/
+
+   if (outside > 0)
+   {
+      grid_boxes = hypre_StructVectorDataSpace(vector);
+   }
+   else
+   {
+      grid_boxes = hypre_StructGridBoxes(hypre_StructVectorGrid(vector));
+   }
+   data_space = hypre_StructVectorDataSpace(vector);
+
+   if (boxnum < 0)
+   {
+      istart = 0;
+      istop  = hypre_BoxArraySize(grid_boxes);
+   }
+   else
+   {
+      istart = boxnum;
+      istop  = istart + 1;
+   }
+
+   /*-----------------------------------------------------------------------
+    * Set the vector coefficients
+    *-----------------------------------------------------------------------*/
+
+   hypre_SetIndex(data_stride, 1, 1, 1);
+ 
+   int_box = hypre_BoxCreate();
+ 
+   for (i = istart; i < istop; i++)
+   {
+      grid_box = hypre_BoxArrayBox(grid_boxes, i);
+      data_box = hypre_BoxArrayBox(data_space, i);
+ 
+      hypre_IntersectBoxes(clear_box, grid_box, int_box);
+
+      /* if there was an intersection */
+      if (int_box)
+      {
+         data_start = hypre_BoxIMin(int_box);
+ 
+         datap = hypre_StructVectorBoxData(vector, i);
+ 
+         hypre_BoxGetSize(int_box, loop_size);
+
+         hypre_BoxLoop1Begin(loop_size,
+                             data_box,data_start,data_stride,datai);
+#define HYPRE_BOX_SMP_PRIVATE loopk,loopi,loopj,datai
+#include "hypre_box_smp_forloop.h"
+         hypre_BoxLoop1For(loopi, loopj, loopk, datai)
+         {
+            datap[datai] = 0.0;
+         }
+         hypre_BoxLoop1End(datai);
+      }
+   }
+
+   hypre_BoxDestroy(int_box);
+
+   return hypre_error_flag;
+}
+
 /*--------------------------------------------------------------------------
  *--------------------------------------------------------------------------*/