diff --git a/mission/tmtc/TmStore.cpp b/mission/tmtc/TmStore.cpp
index 5c3f00c8..d29538ed 100644
--- a/mission/tmtc/TmStore.cpp
+++ b/mission/tmtc/TmStore.cpp
@@ -5,6 +5,7 @@
 #include <algorithm>
 #include <cinttypes>
 #include <filesystem>
+#include <fstream>
 
 using namespace returnvalue;
 
@@ -58,10 +59,18 @@ ReturnValue_t TmStore::storePacket(PusTmReader& reader) {
   if (not mostRecentFile) {
     assignMostRecentFile();
   }
-  // TODO: Need to find the file of the most recent file.
-  // TODO: If file exists: Determine whether file rolls over: Maximum file size reached? Interval
-  //       since last timestamp exceeds rollover interval?
-  // TODO: If file does not exist or rollover criteria met: Create new file with current timestamp.
+
+  if (currentTv.tv_sec < mostRecentTv.value().tv_sec or
+      currentTv.tv_sec - mostRecentTv.value().tv_sec > static_cast<int>(rolloverDiffSeconds)) {
+    if (file_size(mostRecentFile.value()) + reader.getFullPacketLen() > fileBuf.size()) {
+      // TODO: Rename old file to XYZ.1..z , create new file with the same name as old one,
+      //       update most recent file with that name
+    }
+  }
+
+  // Rollover conditions were handled, write to file now
+  std::ofstream of(mostRecentFile.value(), std::ios::app | std::ios::binary);
+  of.write(reinterpret_cast<const char*>(reader.getFullData()), reader.getFullPacketLen());
   return returnvalue::OK;
 }
 
@@ -85,6 +94,8 @@ void TmStore::updateBaseDir() {
   baseDirUninitialized = false;
 }
 
+ReturnValue_t TmStore::updateCurrentTimestamp() { return Clock::getClock_timeval(&currentTv); }
+
 void TmStore::assignMostRecentFile() {
   using namespace std::filesystem;
   for (auto const& file : directory_iterator(baseDir)) {
@@ -113,3 +124,5 @@ void TmStore::assignMostRecentFile() {
     }
   }
 }
+
+ReturnValue_t TmStore::storePacketInternal(PusTmReader& reader) { return returnvalue::OK; }
diff --git a/mission/tmtc/TmStore.h b/mission/tmtc/TmStore.h
index f26461e7..3151a818 100644
--- a/mission/tmtc/TmStore.h
+++ b/mission/tmtc/TmStore.h
@@ -22,6 +22,8 @@ class TmStore : public SystemObject {
   TmStore(object_id_t objectId, std::string baseName, RolloverInterval intervalUnit,
           uint32_t intervalCount, PacketFilter filter, SdCardMountedIF& sdcMan);
 
+  void updateBaseDir();
+  ReturnValue_t updateCurrentTimestamp();
   ReturnValue_t passPacket(PusTmReader& reader);
   ReturnValue_t storePacket(PusTmReader& reader);
 
@@ -38,15 +40,15 @@ class TmStore : public SystemObject {
   std::string baseName;
   std::filesystem::path baseDir;
   uint32_t rolloverDiffSeconds = 0;
-  char NAME_BUF[524] = {};
   std::array<uint8_t, 8192> fileBuf{};
+  timeval currentTv{};
   std::optional<timeval> mostRecentTv;
   std::optional<std::filesystem::path> mostRecentFile;
   SdCardMountedIF& sdcMan;
 
   void calcDiffSeconds(RolloverInterval intervalUnit, uint32_t intervalCount);
-  void updateBaseDir();
   void assignMostRecentFile();
+  ReturnValue_t storePacketInternal(PusTmReader& reader);
 };
 
 #endif /* MISSION_TMTC_TMSTOREBACKEND_H_ */