diff --git a/src/cell.cpp b/src/cell.cpp
index b85e4fd569..c58fb17679 100644
--- a/src/cell.cpp
+++ b/src/cell.cpp
@@ -223,15 +223,15 @@ Universe::find_cell(Particle& p) const {
 
   for (auto it = cells.begin(); it != cells.end(); it++) {
     int32_t i_cell = *it;
-    int32_t i_univ = p.coord_[p.n_coord_-1].universe;
+    int32_t i_univ = p.coord(p.n_coord()-1).universe;
     if (model::cells[i_cell]->universe_ != i_univ) continue;
 
     // Check if this cell contains the particle;
     Position r {p.r_local()};
     Direction u {p.u_local()};
-    auto surf = p.surface_;
+    auto surf = p.surface();
     if (model::cells[i_cell]->contains(r, u, surf)) {
-      p.coord_[p.n_coord_-1].cell = i_cell;
+      p.coord(p.n_coord()-1).cell = i_cell;
       return true;
     }
   }
diff --git a/src/dagmc.cpp b/src/dagmc.cpp
index 5254035794..5932e04a12 100644
--- a/src/dagmc.cpp
+++ b/src/dagmc.cpp
@@ -355,7 +355,7 @@ DAGUniverse::find_cell(Particle &p) const {
   // cells, place it in the implicit complement
   bool found = Universe::find_cell(p);
   if (!found && model::universe_map[this->id_] != model::root_universe) {
-    p.coord_[p.n_coord_ - 1].cell = implicit_complement_idx();
+    p.coord(p.n_coord() - 1).cell = implicit_complement_idx();
     found = true;
   }
   return found;
@@ -504,10 +504,10 @@ DAGCell::distance(Position r, Direction u, int32_t on_surface, Particle* p) cons
   Expects(p);
   // if we've changed direction or we're not on a surface,
   // reset the history and update last direction
-  if (u != p->last_dir_) { p->last_dir_ = u; p->history_.reset(); }
-  if (on_surface == 0) { p->history_.reset(); }
+  if (u != p->last_dir()) { p->last_dir() = u; p->history().reset(); }
+  if (on_surface == 0) { p->history().reset(); }
 
-  const auto& univ = model::universes[p->coord_[p->n_coord_ - 1].universe];
+  const auto& univ = model::universes[p->coord(p->n_coord() - 1).universe];
 
   DAGUniverse* dag_univ = static_cast<DAGUniverse*>(univ.get());
   if (!dag_univ) fatal_error("DAGMC call made for particle in a non-DAGMC universe");
@@ -518,7 +518,7 @@ DAGCell::distance(Position r, Direction u, int32_t on_surface, Particle* p) cons
   double dist;
   double pnt[3] = {r.x, r.y, r.z};
   double dir[3] = {u.x, u.y, u.z};
-  rval = dagmc_ptr_->ray_fire(vol, pnt, dir, hit_surf, dist, &p->history_);
+  rval = dagmc_ptr_->ray_fire(vol, pnt, dir, hit_surf, dist, &p->history());
   MB_CHK_ERR_CONT(rval);
   int surf_idx;
   if (hit_surf != 0) {
@@ -610,15 +610,15 @@ Direction
 DAGSurface::reflect(Position r, Direction u, Particle* p) const
 {
   Expects(p);
-  p->history_.reset_to_last_intersection();
+  p->history().reset_to_last_intersection();
   moab::ErrorCode rval;
   moab::EntityHandle surf = dagmc_ptr_->entity_by_index(2, dag_index_);
   double pnt[3] = {r.x, r.y, r.z};
   double dir[3];
-  rval = dagmc_ptr_->get_angle(surf, pnt, dir, &p->history_);
+  rval = dagmc_ptr_->get_angle(surf, pnt, dir, &p->history());
   MB_CHK_ERR_CONT(rval);
-  p->last_dir_ = u.reflect(dir);
-  return p->last_dir_;
+  p->last_dir() = u.reflect(dir);
+  return p->last_dir();
 }
 
 //==============================================================================
diff --git a/src/geometry.cpp b/src/geometry.cpp
index efa993b061..c93e1940b6 100644
--- a/src/geometry.cpp
+++ b/src/geometry.cpp
@@ -117,7 +117,7 @@ find_cell_inner(Particle& p, const NeighborList* neighbor_list)
     }
 
     if (!found) { return found; }
-    i_cell = p.coord_[p.n_coord_ - 1].cell;
+    i_cell = p.coord(p.n_coord() - 1).cell;
 
     // Announce the cell that the particle is entering.
     if (found && (settings::verbosity >= 10 || p.trace())) {
diff --git a/src/particle.cpp b/src/particle.cpp
index 2f0f52e63d..de1b2431fe 100644
--- a/src/particle.cpp
+++ b/src/particle.cpp
@@ -288,7 +288,7 @@ Particle::event_collide()
   if (!model::active_tallies.empty()) score_collision_derivative(*this);
 
   #ifdef DAGMC
-  history_.reset();
+  history().reset();
   #endif
 }
 
@@ -323,7 +323,7 @@ void
 Particle::event_death()
 {
   #ifdef DAGMC
-  history_.reset();
+  history().reset();
   #endif
 
   // Finish particle track output.
@@ -394,18 +394,18 @@ Particle::cross_surface()
   // in DAGMC, we know what the next cell should be
   if (surf->geom_type_ == GeometryType::DAG) {
     auto surfp = dynamic_cast<DAGSurface*>(surf);
-    auto cellp = dynamic_cast<DAGCell*>(model::cells[cell_last_[n_coord_ - 1]].get());
-    auto univp = static_cast<DAGUniverse*>(model::universes[coord_[n_coord_ - 1].universe].get());
+    auto cellp = dynamic_cast<DAGCell*>(model::cells[cell_last(n_coord() - 1)].get());
+    auto univp = static_cast<DAGUniverse*>(model::universes[coord(n_coord() - 1).universe].get());
     // determine the next cell for this crossing
     int32_t i_cell = next_cell(univp, cellp, surfp) - 1;
     // save material and temp
-    material_last_ = material_;
-    sqrtkT_last_ = sqrtkT_;
+    material_last() = material();
+    sqrtkT_last() = sqrtkT();
     // set new cell value
-    coord_[n_coord_ - 1].cell = i_cell;
-    cell_instance_ = 0;
-    material_ = model::cells[i_cell]->material_[0];
-    sqrtkT_ = model::cells[i_cell]->sqrtkT_[0];
+    coord(n_coord() - 1).cell = i_cell;
+    cell_instance() = 0;
+    material() = model::cells[i_cell]->material_[0];
+    sqrtkT() = model::cells[i_cell]->sqrtkT_[0];
     return;
   }
 #endif
@@ -506,7 +506,7 @@ Particle::cross_reflective_bc(const Surface& surf, Direction new_u)
 
   // if we're crossing a CSG surface, make sure the DAG history is reset
   #ifdef DAGMC
-  if (surf.geom_type_ != GeometryType::DAG) history_.reset();
+  if (surf.geom_type_ != GeometryType::DAG) history().reset();
   #endif
 
   // If a reflective surface is coincident with a lattice or universe