diff --git a/nag b/nag
index ba7ba3f..b0f7a68 100755
--- a/nag
+++ b/nag
@@ -704,9 +704,9 @@ _is_snoozed() {
 #   _sweep_expired_snoozes
 #
 # Description:
-#   Remove expired snooze entries (those whose expiry timestamp is in the
-#   past). Indefinite entries (no expiry) are kept. If all entries are
-#   removed, the snoozed file is deleted.
+#   Remove stale snooze entries: expired (past expiry timestamp) and
+#   orphaned (alarm ID no longer exists in _ALARMS). Expects _ALARMS
+#   to be populated via _read_alarms before calling.
 _sweep_expired_snoozes() {
   [[ -f "${_SNOOZED_FILE}" ]] || return 0
 
@@ -718,11 +718,25 @@ _sweep_expired_snoozes() {
   while IFS= read -r _entry || [[ -n "${_entry}" ]]
   do
     [[ -n "${_entry}" ]] || continue
+
+    local _entry_id="${_entry%%$'\t'*}"
+
+    # Drop expired entries.
     if [[ "${_entry}" == *$'\t'* ]]
     then
       local _expiry="${_entry#*$'\t'}"
       (( _expiry <= _now )) && continue
     fi
+
+    # Drop orphaned entries (alarm no longer exists).
+    local _exists=0 _line
+    for _line in "${_ALARMS[@]:-}"
+    do
+      [[ -n "${_line}" ]] || continue
+      [[ "${_line%%$'\t'*}" == "${_entry_id}" ]] && _exists=1 && break
+    done
+    (( _exists )) || continue
+
     _keep+=("${_entry}")
   done < "${_SNOOZED_FILE}"
 
@@ -808,6 +822,16 @@ _remove_snoozed_entry() {
   return 0
 }
 
+# Usage:
+#   _cleanup_alarm_metadata <id>
+#
+# Description:
+#   Remove all metadata for an alarm ID (snoozed file entries).
+#   Called when an alarm is permanently removed.
+_cleanup_alarm_metadata() {
+  _remove_snoozed_entry "${1}" 2>/dev/null || true
+}
+
 # Usage:
 #   _tag_list <tag>
 #
@@ -1664,6 +1688,7 @@ stop() {
     _ALARMS=("${_new_alarms[@]}")
     _write_alarms
   fi
+  _cleanup_alarm_metadata "${_target}"
   _release_lock
 
   printf "Stopped alarm %s.\\n" "${_target}"
@@ -1712,7 +1737,6 @@ _stop_by_tag() {
     _ALARMS=("${_new_alarms[@]}")
     _write_alarms
   fi
-  _release_lock
 
   local _m
   for _m in "${_matched[@]}"
@@ -1720,8 +1744,10 @@ _stop_by_tag() {
     local _id _message
     _id="${_m%%$'\t'*}"
     _message="$(_get_alarm_field "${_m}" 5)"
+    _cleanup_alarm_metadata "${_id}"
     printf "Stopped [%s] %s\\n" "${_id}" "${_message}"
   done
+  _release_lock
 }
 
 _stop_all() {
@@ -1747,6 +1773,7 @@ _stop_all() {
     local _id _message
     _id="${_line%%$'\t'*}"
     _message="$(_get_alarm_field "${_line}" 5)"
+    _cleanup_alarm_metadata "${_id}"
     printf "Stopped [%s] %s\\n" "${_id}" "${_message}"
   done
 
@@ -1811,6 +1838,7 @@ skip() {
         _human_time="${REPLY}"
         printf "Skipped [%s] %s — next: %s\\n" "${_id}" "${_message}" "${_human_time}"
       else
+        _cleanup_alarm_metadata "${_id}"
         printf "Stopped [%s] %s\\n" "${_id}" "${_message}"
       fi
     else
@@ -1889,6 +1917,7 @@ _skip_by_tag() {
         _human_time="${REPLY}"
         printf "Skipped [%s] %s — next: %s\\n" "${_id}" "${_message}" "${_human_time}"
       else
+        _cleanup_alarm_metadata "${_id}"
         printf "Stopped [%s] %s\\n" "${_id}" "${_message}"
       fi
     else
@@ -1945,6 +1974,7 @@ _skip_all() {
       _human_time="${REPLY}"
       printf "Skipped [%s] %s — next: %s\\n" "${_id}" "${_message}" "${_human_time}"
     else
+      _cleanup_alarm_metadata "${_id}"
       printf "Stopped [%s] %s\\n" "${_id}" "${_message}"
     fi
   done
diff --git a/test/check.bats b/test/check.bats
index 74fb6b1..1d1cbab 100644
--- a/test/check.bats
+++ b/test/check.bats
@@ -197,3 +197,19 @@ SCRIPT
   [ "${status}" -eq 0 ]
   grep -q "expired snooze" "${_fired}"
 }
+
+@test "check sweeps orphaned snooze entries for removed alarms" {
+  local _future_ts=$(( $(date +%s) + 3600 ))
+  write_alarm "$(printf "2\t\t%s\t\treal alarm" "${_future_ts}")"
+  # ID 1 does not exist in alarms, ID 2 does.
+  printf "1\\n" > "${NAG_DIR}/snoozed"
+  printf "2\\n" >> "${NAG_DIR}/snoozed"
+
+  run_nag check
+  [ "${status}" -eq 0 ]
+
+  # Orphan ID 1 should be swept, ID 2 should remain.
+  [ -f "${NAG_DIR}/snoozed" ]
+  ! grep -q "^1$" "${NAG_DIR}/snoozed"
+  grep -q "^2$" "${NAG_DIR}/snoozed"
+}
\ No newline at end of file
diff --git a/test/skip.bats b/test/skip.bats
index 774ddb8..a83288f 100644
--- a/test/skip.bats
+++ b/test/skip.bats
@@ -87,3 +87,15 @@ load test_helper
   run "${_NAG}" -f skip all
   [ "${status}" -eq 1 ]
 }
+
+@test "skip one-shot cleans up snoozed metadata" {
+  run_nag at "tomorrow 3pm" "one-shot"
+  run_nag snooze 1
+  [ -f "${NAG_DIR}/snoozed" ]
+  run_nag skip 1
+  [ "${status}" -eq 0 ]
+  [[ "${output}" =~ "Stopped" ]]
+  if [ -f "${NAG_DIR}/snoozed" ]; then
+    ! grep -q "^1" "${NAG_DIR}/snoozed"
+  fi
+}
diff --git a/test/stop.bats b/test/stop.bats
index c9b50b2..90d211a 100644
--- a/test/stop.bats
+++ b/test/stop.bats
@@ -85,3 +85,36 @@ load test_helper
   run "${_NAG}" -f stop all
   [ "${status}" -eq 1 ]
 }
+
+@test "stop by ID cleans up snoozed metadata" {
+  run_nag at "tomorrow 3pm" "take a break"
+  run_nag snooze 1
+  [ -f "${NAG_DIR}/snoozed" ]
+  run_nag stop 1
+  [ "${status}" -eq 0 ]
+  if [ -f "${NAG_DIR}/snoozed" ]; then
+    ! grep -q "^1" "${NAG_DIR}/snoozed"
+  fi
+}
+
+@test "stop by tag cleans up snoozed metadata" {
+  run_nag at "tomorrow 3pm" "work task"
+  run_nag tag 1 work
+  run_nag snooze 1
+  [ -f "${NAG_DIR}/snoozed" ]
+  run "${_NAG}" -f stop work
+  [ "${status}" -eq 0 ]
+  if [ -f "${NAG_DIR}/snoozed" ]; then
+    ! grep -q "^1" "${NAG_DIR}/snoozed"
+  fi
+}
+
+@test "stop all cleans up snoozed metadata" {
+  run_nag at "tomorrow 3pm" "first"
+  run_nag at "tomorrow 4pm" "second"
+  run_nag snooze all
+  [ -f "${NAG_DIR}/snoozed" ]
+  run "${_NAG}" -f stop all
+  [ "${status}" -eq 0 ]
+  [ ! -f "${NAG_DIR}/snoozed" ] || [ ! -s "${NAG_DIR}/snoozed" ]
+}