diff --git a/ProcessLib/DeactivatedSubdomain.cpp b/ProcessLib/DeactivatedSubdomain.cpp
index 042320e56112bb1c3c7d83a4bac43d48c2b0d189..da8c9eeef3cc53f52eceba7d2a25e2baac5a2ac8 100644
--- a/ProcessLib/DeactivatedSubdomain.cpp
+++ b/ProcessLib/DeactivatedSubdomain.cpp
@@ -47,6 +47,11 @@ DeactivatedSubdomain::DeactivatedSubdomain(
 {
 }
 
+bool DeactivatedSubdomain::includesTimeOf(double const t) const
+{
+    return time_interval->contains(t);
+}
+
 std::unique_ptr<DeactivatedSubdomain const> createDeactivatedSubdomain(
     BaseLib::ConfigTree const& config, MeshLib::Mesh const& mesh)
 {
diff --git a/ProcessLib/DeactivatedSubdomain.h b/ProcessLib/DeactivatedSubdomain.h
index 5abf4f2bde6128b020ea37d0392489d6486201cb..ca9bc013cf8728f94f55cd2c1e652ae7664b86bb 100644
--- a/ProcessLib/DeactivatedSubdomain.h
+++ b/ProcessLib/DeactivatedSubdomain.h
@@ -21,13 +21,13 @@ namespace BaseLib
 {
 class ConfigTree;
 class TimeInterval;
-}
+}  // namespace BaseLib
 
 namespace MeshLib
 {
 class Mesh;
 class Node;
-}
+}  // namespace MeshLib
 
 namespace ProcessLib
 {
@@ -49,6 +49,8 @@ struct DeactivatedSubdomain
         std::vector<std::unique_ptr<DeactivetedSubdomainMesh>>&&
             deactivated_sudomain_meshes_);
 
+    bool includesTimeOf(double const t) const;
+
     std::unique_ptr<BaseLib::TimeInterval const> time_interval;
 
     /// The material IDs of the deactivated the subdomains
@@ -64,4 +66,4 @@ std::vector<std::unique_ptr<DeactivatedSubdomain const>>
 createDeactivatedSubdomains(BaseLib::ConfigTree const& config,
                             MeshLib::Mesh const& mesh);
 
-}  // end of namespace
+}  // namespace ProcessLib
diff --git a/ProcessLib/ProcessVariable.cpp b/ProcessLib/ProcessVariable.cpp
index 0b7fb131da6ad0a767390e765b95d9fe3f35c846..6785d6af58f67373ae4f4412f7c309dc7296b794 100644
--- a/ProcessLib/ProcessVariable.cpp
+++ b/ProcessLib/ProcessVariable.cpp
@@ -9,6 +9,8 @@
 
 #include "ProcessVariable.h"
 
+#include <iostream>
+
 #include <algorithm>
 #include <utility>
 
@@ -55,8 +57,6 @@ MeshLib::Mesh const& findMeshInConfig(
     }
     else
     {
-        // Looking for the mesh created before for the given geometry.
-
 #ifdef DOXYGEN_DOCU_ONLY
         //! \ogs_file_param{prj__process_variables__process_variable__source_terms__source_term__geometrical_set}
         config.getConfigParameterOptional<std::string>("geometrical_set");
@@ -64,6 +64,7 @@ MeshLib::Mesh const& findMeshInConfig(
         config.getConfigParameter<std::string>("geometry");
 #endif  // DOXYGEN_DOCU_ONLY
 
+        // Looking for the mesh created before for the given geometry.
         auto const geometrical_set_name =
             //! \ogs_file_param{prj__process_variables__process_variable__boundary_conditions__boundary_condition__geometrical_set}
             config.getConfigParameter<std::string>("geometrical_set");
@@ -237,11 +238,6 @@ void ProcessVariable::createBoundaryConditionsForDeactivatedSubDomains(
 
     for (auto const& deactivated_subdomain : _deactivated_subdomains)
     {
-        // Copy the time interval.
-        std::unique_ptr<BaseLib::TimeInterval> time_interval =
-            std::make_unique<BaseLib::TimeInterval>(
-                (*(*deactivated_subdomain).time_interval));
-
         auto const& deactivated_sudomain_meshes =
             (*deactivated_subdomain).deactivated_sudomain_meshes;
         for (auto const& deactivated_sudomain_mesh :
@@ -251,6 +247,11 @@ void ProcessVariable::createBoundaryConditionsForDeactivatedSubDomains(
                  component_id < dof_table.getNumberOfComponents();
                  component_id++)
             {
+                // Copy the time interval.
+                std::unique_ptr<BaseLib::TimeInterval> time_interval =
+                    std::make_unique<BaseLib::TimeInterval>(
+                        (*(*deactivated_subdomain).time_interval));
+
                 auto bc = std::make_unique<
                     DirichletBoundaryConditionWithinTimeInterval>(
                     std::move(time_interval), parameter,
@@ -270,6 +271,46 @@ void ProcessVariable::createBoundaryConditionsForDeactivatedSubDomains(
     }
 }
 
+void ProcessVariable::checkElementDeactivation(double const time)
+{
+    if (_deactivated_subdomains.empty())
+    {
+        _element_deactivation_flags.clear();
+        return;
+    }
+
+    auto found_a_set =
+        std::find_if(_deactivated_subdomains.begin(),
+                     _deactivated_subdomains.end(),
+                     [&](auto& _deactivated_subdomain) {
+                         return _deactivated_subdomain->includesTimeOf(time);
+                     });
+
+    if (found_a_set == _deactivated_subdomains.end())
+    {
+        _element_deactivation_flags.clear();
+        return;
+    }
+
+    // Already initialized.
+    if (!_element_deactivation_flags.empty())
+        return;
+
+    auto const& deactivated_materialIDs = (*found_a_set)->materialIDs;
+
+    auto const* const material_ids = MeshLib::materialIDs(_mesh);
+    _element_deactivation_flags.resize(_mesh.getNumberOfElements());
+    auto const number_of_elements = _mesh.getNumberOfElements();
+
+    for (std::size_t i = 0; i < number_of_elements; i++)
+    {
+        _element_deactivation_flags[i] =
+            std::binary_search(deactivated_materialIDs.begin(),
+                               deactivated_materialIDs.end(),
+                               (*material_ids)[i]);
+    }
+}
+
 std::vector<std::unique_ptr<SourceTerm>> ProcessVariable::createSourceTerms(
     const NumLib::LocalToGlobalIndexMap& dof_table,
     const int variable_id,
diff --git a/ProcessLib/ProcessVariable.h b/ProcessLib/ProcessVariable.h
index 2d38f678cadf32bbc1dcc971836e1119acb2dd60..0474db4f53de38ad81727f18d174703e1c44b1a8 100644
--- a/ProcessLib/ProcessVariable.h
+++ b/ProcessLib/ProcessVariable.h
@@ -60,6 +60,13 @@ public:
         return _deactivated_subdomains;
     }
 
+    void checkElementDeactivation(double const time);
+
+    std::vector<bool>& getElementDeactivationFlags() const
+    {
+        return _element_deactivation_flags;
+    }
+
     /// Returns the number of components of the process variable.
     int getNumberOfComponents() const { return _n_components; }
     std::vector<std::unique_ptr<BoundaryCondition>> createBoundaryConditions(
@@ -101,6 +108,8 @@ private:
     std::vector<std::unique_ptr<DeactivatedSubdomain const>>
         _deactivated_subdomains;
 
+    mutable std::vector<bool> _element_deactivation_flags;
+
     void createBoundaryConditionsForDeactivatedSubDomains(
         const NumLib::LocalToGlobalIndexMap& dof_table, const int variable_id,
         std::vector<std::unique_ptr<ParameterBase>> const& parameters,