diff --git a/CHANGELOG.md b/CHANGELOG.md
index dc5540f4..9c7b7fe5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Micro Manager changelog
 
+## latest
+
+- Allow `initialize()` to return data that is not used by the adaptivity [#261](https://github.com/precice/micro-manager/pull/261)
+
 ## v0.9.0
 
 - Refactored `DomainDecomposer` class and added a new variant of non-uniform decomposition [#243](https://github.com/precice/micro-manager/pull/243)
diff --git a/micro_manager/micro_manager.py b/micro_manager/micro_manager.py
index 64239a35..bbe74d7b 100644
--- a/micro_manager/micro_manager.py
+++ b/micro_manager/micro_manager.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+#!/usr/bin/env python3micro_manager
 """
 Micro Manager is a tool to initialize and adaptively control micro simulations and couple them via preCICE to a macro simulation.
 This files the class MicroManager which has the following callable public methods:
@@ -742,6 +742,20 @@ def initialize(self) -> None:
                         self._micro_sims[i].initialize()
             else:  # Case where the initialize() method returns data
                 if self._is_adaptivity_on:
+                    # Check for missing data
+                    expected, provided = set(self._data_for_adaptivity.keys()), set(
+                        initial_micro_output.keys()
+                    )
+                    if missing := expected - provided:
+                        raise Exception(
+                            "The initialize() method needs to return data which is required for the adaptivity calculation. "
+                            f'Of the expected data {", ".join(expected)}, the following is missing: {", ".join(missing)}'
+                        )
+                    elif extra := provided - expected:
+                        self._logger.log_warning_rank_zero(
+                            f'The initialize() method of the Micro simulation returns extra initial data which isn\'t used by the adaptivity: {", ".join(extra)}'
+                        )
+
                     for name in initial_micro_output.keys():
                         initial_micro_data[name] = [0] * self._local_number_of_sims
                         # Save initial data from first micro simulation as we anyway have it
@@ -750,12 +764,8 @@ def initialize(self) -> None:
                     # Save initial data from first micro simulation as we anyway have it
                     for name in initial_micro_output.keys():
                         if name in self._data_for_adaptivity:
-                            self._data_for_adaptivity[name][
-                                first_id
-                            ] = initial_micro_output[name]
-                        else:
-                            raise Exception(
-                                "The initialize() method needs to return data which is required for the adaptivity calculation."
+                            self._data_for_adaptivity[name][first_id] = (
+                                initial_micro_output[name]
                             )
 
                     # Gather initial data from the rest of the micro simulations
@@ -765,17 +775,17 @@ def initialize(self) -> None:
                                 initial_macro_data[i]
                             )
                             for name in self._adaptivity_micro_data_names:
-                                self._data_for_adaptivity[name][
-                                    i
-                                ] = initial_micro_output[name]
+                                self._data_for_adaptivity[name][i] = (
+                                    initial_micro_output[name]
+                                )
                                 initial_micro_data[name][i] = initial_micro_output[name]
                     else:
                         for i in micro_sims_to_init:
                             initial_micro_output = self._micro_sims[i].initialize()
                             for name in self._adaptivity_micro_data_names:
-                                self._data_for_adaptivity[name][
-                                    i
-                                ] = initial_micro_output[name]
+                                self._data_for_adaptivity[name][i] = (
+                                    initial_micro_output[name]
+                                )
                                 initial_micro_data[name][i] = initial_micro_output[name]
                 else:  # If adaptivity is off, the returned initial data from the initialize() method will be ignored
                     self._logger.log_warning_rank_zero(
@@ -1045,9 +1055,9 @@ def _solve_micro_simulations_with_adaptivity(
                     # Mark the micro sim as active for export
                     micro_sims_output[lid]["Active-State"] = 1
                     gid = self._global_ids_of_local_sims[lid]
-                    micro_sims_output[lid][
-                        "Active-Steps"
-                    ] = self._micro_sims_active_steps[gid]
+                    micro_sims_output[lid]["Active-Steps"] = (
+                        self._micro_sims_active_steps[gid]
+                    )
 
                 # If simulation crashes, log the error and keep the output constant at the previous iteration's output
                 except Exception as error_message:
@@ -1101,9 +1111,9 @@ def _solve_micro_simulations_with_adaptivity(
         for inactive_lid in inactive_sim_lids:
             micro_sims_output[inactive_lid]["Active-State"] = 0
             gid = self._global_ids_of_local_sims[inactive_lid]
-            micro_sims_output[inactive_lid][
-                "Active-Steps"
-            ] = self._micro_sims_active_steps[gid]
+            micro_sims_output[inactive_lid]["Active-Steps"] = (
+                self._micro_sims_active_steps[gid]
+            )
 
         # Collect micro sim output for adaptivity calculation
         for i in range(self._local_number_of_sims):