diff --git a/application/controllers/components/Antrag/Unterbrechung.php b/application/controllers/components/Antrag/Unterbrechung.php
index 33bd0035d..efc2c3a88 100644
--- a/application/controllers/components/Antrag/Unterbrechung.php
+++ b/application/controllers/components/Antrag/Unterbrechung.php
@@ -86,7 +86,7 @@ class Unterbrechung extends FHC_Controller
 
 		$data = getData($result);
 
-		$data->studiensemester = $this->antraglib->getSemesterForUnterbrechung($data->studiensemester_kurzbz);
+		$data->studiensemester = $this->antraglib->getSemesterForUnterbrechung($prestudent_id, $data->studiensemester_kurzbz);
 
 		$this->outputJsonSuccess($data);
 	}
@@ -136,7 +136,7 @@ class Unterbrechung extends FHC_Controller
 		$datum_wiedereinstieg = $this->input->post('datum_wiedereinstieg');
 		$dms_id = null;
 
-		$result = $this->antraglib->getPrestudentUnterbrechungsBerechtigt($prestudent_id);
+		$result = $this->antraglib->getPrestudentUnterbrechungsBerechtigt($prestudent_id, $studiensemester, $datum_wiedereinstieg);
 		if (isError($result)) {
 			return $this->outputJsonError(['db' => getError($result)]);
 		}
diff --git a/application/libraries/AntragLib.php b/application/libraries/AntragLib.php
index f094440e2..d8ef224db 100644
--- a/application/libraries/AntragLib.php
+++ b/application/libraries/AntragLib.php
@@ -1302,7 +1302,7 @@ class AntragLib
 	 * 						retval -2 means other Antrag pending;
 	 * 						retval -3 means in blacklist stg
 	 */
-	public function getPrestudentUnterbrechungsBerechtigt($prestudent_id, $studiensemester_kurzbz = null)
+	public function getPrestudentUnterbrechungsBerechtigt($prestudent_id, $studiensemester_kurzbz = null, $datum_wiedereinstieg = null)
 	{
 		$result = $this->_ci->PrestudentModel->load($prestudent_id);
 		if (isError($result))
@@ -1320,18 +1320,10 @@ class AntragLib
 		if (!hasData($result))
 			return success(0);
 		$result = current(getData($result));
+		$prestudent_stdsem = $result->studiensemester_kurzbz;
 		$datumStatus = $result->datum;
-		if (!in_array($result->status_kurzbz, $this->_ci->config->item('antrag_prestudentstatus_whitelist'))) {
-			$result = $this->_ci->StudierendenantragModel->loadWithStatusWhere([
-				'prestudent_id' => $prestudent_id,
-				'typ' => Studierendenantrag_model::TYP_UNTERBRECHUNG,
-				'campus.get_status_studierendenantrag(studierendenantrag_id)' => Studierendenantragstatus_model::STATUS_APPROVED
-			]);
-			if (isError($result))
-				return $result;
-			if (hasData($result))
-				return success(-1);
-
+		if (!in_array($result->status_kurzbz, $this->_ci->config->item('antrag_prestudentstatus_whitelist'))
+			&& $result->status_kurzbz != 'Unterbrecher') {
 			return success(0);
 		}
 		$result = $this->_ci->StudierendenantragModel->loadWithStatusWhere(['prestudent_id' => $prestudent_id]);
@@ -1339,7 +1331,8 @@ class AntragLib
 			return $result;
 		if (!hasData($result))
 			return success(1);
-		$result= getData($result);
+
+		$result = getData($result);
 		foreach ($result as $antrag)
 		{
 			if ($antrag->typ == Studierendenantrag_model::TYP_ABMELDUNG || $antrag->typ == Studierendenantrag_model::TYP_ABMELDUNG_STGL)
@@ -1349,11 +1342,11 @@ class AntragLib
 				elseif($antrag->status == Studierendenantragstatus_model::STATUS_APPROVED && $antrag->datum > $datumStatus)
 					return success(-2);
 			}
-			if ($studiensemester_kurzbz && $antrag->typ == Studierendenantrag_model::TYP_UNTERBRECHUNG)
+			if ($antrag->typ == Studierendenantrag_model::TYP_UNTERBRECHUNG)
 			{
-				// NOTE(chris): check if this is an old or canceled one
-				if ($antrag->studiensemester_kurzbz == $studiensemester_kurzbz && $antrag->status != Studierendenantragstatus_model::STATUS_CANCELLED)
-					return success(-1);
+				// NOTE(chris): Ignore canceled ones
+				if ($antrag->status == Studierendenantragstatus_model::STATUS_CANCELLED)
+					continue;
 			}
 			if ($antrag->typ == Studierendenantrag_model::TYP_WIEDERHOLUNG)
 			{
@@ -1362,6 +1355,17 @@ class AntragLib
 			}
 		}
 
+		if (!$studiensemester_kurzbz) {
+			$sems = $this->getSemesterForUnterbrechung($prestudent_id, $prestudent_stdsem);
+			if (!count(array_filter($sems, function ($item) {
+				return !$item['disabled'];
+			})))
+				return success(-1);
+		} else {
+			if ($this->_ci->StudierendenantragModel->hasRunningUnterbrechungBetween($prestudent_id, $studiensemester_kurzbz, $datum_wiedereinstieg))
+				return success(-1);
+		}
+		
 		return success(1);
 	}
 
@@ -1552,53 +1556,43 @@ class AntragLib
 		return success($resultDetails);
 	}
 
-	public function getSemesterForUnterbrechung($studiensemester_kurzbz)
+	/**
+	 * Rearrange the free semester slots for a new Unterbrechung
+	 * 
+	 * @param integer		$prestudent_id
+	 * @param string		$studiensemester_kurzbz
+	 * 
+	 * @return array
+	 */
+	public function getSemesterForUnterbrechung($prestudent_id, $studiensemester_kurzbz)
 	{
-		$this->_ci->load->model('organisation/Studiensemester_model', 'StudiensemesterModel');
-
-		$semester = [];
-
-		$result = $this->_ci->StudiensemesterModel->getNextFrom($studiensemester_kurzbz);
-		if (!hasData($result))
-			return $semester;
-		$nextSem = current(getData($result));
-
-		$semester[0] = [
-			'studiensemester_kurzbz' => $studiensemester_kurzbz,
-			'wiedereinstieg' => [$nextSem]
-		];
-
-		$result = $this->_ci->StudiensemesterModel->getNextFrom($nextSem->studiensemester_kurzbz);
-		if (!hasData($result))
-			return $semester;
-
-		$currSemester = current(getData($result));
-		$followingSemester = [$currSemester];
-
-		$max = $this->_ci->config->item('unterbrecher_semester_max_length');
-		if(!$max || $max < 1)
-			$max = 2;
-
-		for ($i = 1; $i < $max; $i++) {
-			$result = $this->_ci->StudiensemesterModel->getNextFrom($currSemester->studiensemester_kurzbz);
-			if (!hasData($result))
-				break;
-			$currSemester = current(getData($result));
-			$followingSemester[] = $currSemester;
-		}
-
-		$semester[1] = [
-			'studiensemester_kurzbz' => $nextSem->studiensemester_kurzbz,
-			'wiedereinstieg' => $followingSemester
-		];
-
-		//remove last Semester of the array
-		array_pop($followingSemester);
-
-		foreach ($followingSemester as $sem)
-			$semester[0]['wiedereinstieg'][] = $sem;
-
-		return $semester;
+		$result = $this->_ci->StudierendenantragModel->getFreeSlotsForUnterbrechung($prestudent_id, $studiensemester_kurzbz);
+		if (isError($result))
+			return [];
+		$result = getData($result);
+		if (!$result)
+			return [];
+		return array_reduce($result, function ($carry, $item) {
+			if (!isset($carry[$item->von]))
+				$carry[$item->von] = [
+					'studiensemester_kurzbz' => $item->von,
+					'wiedereinstieg' => [],
+					'disabled' => true
+				];
+			
+			$carry[$item->von]['wiedereinstieg'][] = [
+				'studiensemester_kurzbz' => $item->bis,
+				'start' => $item->ende,
+				'disabled' => (boolean)$item->studierendenantrag_id
+			];
+			
+			if ($carry[$item->von]['disabled'] && !$item->studierendenantrag_id) {
+				$carry[$item->von]['disabled'] = false;
+			}
+			
+			return $carry;
+		}, []);
+		return $result;
 	}
 
 	public function getAktivePrestudentenInStgs($studiengaenge, $query)
diff --git a/application/models/education/Studierendenantrag_model.php b/application/models/education/Studierendenantrag_model.php
index ea481ebef..9edc7ef91 100644
--- a/application/models/education/Studierendenantrag_model.php
+++ b/application/models/education/Studierendenantrag_model.php
@@ -287,4 +287,98 @@ class Studierendenantrag_model extends DB_Model
 
 		return $this->loadWhere($where);
 	}
+
+	/**
+	 * Checks if the Prestudent has an active Unterbrechung between
+	 * the start of the given semester and the given enddate.
+	 * If the enddate is omitted the end of the given semester is used.
+	 *
+	 * @param integer		$prestudent_id
+	 * @param string		$studiensemester_kurzbz
+	 * @param string		$enddate					(optional)
+	 *
+	 * @return boolean
+	 */
+	public function hasRunningUnterbrechungBetween($prestudent_id, $studiensemester, $enddate = null)
+	{
+		$start = '(SELECT start FROM public.tbl_studiensemester WHERE studiensemester_kurzbz=' . $this->db->escape($studiensemester) . ')';
+		$end = $enddate
+			? $this->db->escape($enddate)
+			: '(SELECT ende FROM public.tbl_studiensemester WHERE studiensemester_kurzbz=' . $this->db->escape($studiensemester) . ')';
+
+		$this->addJoin('public.tbl_studiensemester', 'studiensemester_kurzbz');
+		$this->db->where([
+			'prestudent_id' => $prestudent_id,
+			'typ' => Studierendenantrag_model::TYP_UNTERBRECHUNG,
+			'campus.get_status_studierendenantrag(studierendenantrag_id) !=' => Studierendenantragstatus_model::STATUS_CANCELLED,
+			'start < ' . $end => null,
+			'datum_wiedereinstieg > ' . $start => null,
+		]);
+		return (boolean)$this->db->count_all_results($this->dbTable);
+	}
+
+	/**
+	 * Gets free semester slots for a new Unterbrechung.
+	 *
+	 * @param integer		$prestudent_id
+	 * @param string		$studiensemester_kurzbz		(optional)
+	 *
+	 * @return stdClass
+	 */
+	public function getFreeSlotsForUnterbrechung($prestudent_id, $studiensemester = null)
+	{
+		$max_starters = 2;
+		$max_length = max(
+			2,
+			(integer)$this->config->item('unterbrecher_semester_max_length')
+		);
+
+
+		$subquery = '';
+		if ($studiensemester)
+			$subquery = 'SELECT start FROM public.tbl_studiensemester WHERE studiensemester_kurzbz=?';
+		else
+			$subquery = 'SELECT start FROM public.tbl_studiensemester WHERE studiensemester_kurzbz=public.get_stdsem_prestudent (?, null)';
+
+		$sql = "WITH numbered_sems AS (
+		    SELECT
+		        a.studiensemester_kurzbz AS von,
+		        b.studiensemester_kurzbz AS bis,
+		        a.start AS start,
+		        b.start AS ende,
+		        ROW_NUMBER() OVER (
+		            PARTITION BY a.studiensemester_kurzbz
+		            ORDER BY b.start
+		        ) AS row_number
+		    FROM public.tbl_studiensemester a
+		    LEFT JOIN public.tbl_studiensemester b ON (b.start > a.ende)
+		),
+		last_sems AS (
+		    SELECT *
+		    FROM numbered_sems 
+		    WHERE numbered_sems.row_number <= ?
+		)
+		SELECT s.von, s.bis, s.start, s.ende, studierendenantrag_id
+		FROM last_sems s
+		LEFT JOIN (
+			SELECT studierendenantrag_id, start, datum_wiedereinstieg AS ende 
+			FROM campus.tbl_studierendenantrag 
+			LEFT JOIN public.tbl_studiensemester USING(studiensemester_kurzbz) 
+			WHERE typ=? 
+			AND campus.get_status_studierendenantrag(studierendenantrag_id) != ?
+			AND prestudent_id=?
+		) a ON (s.start < a.ende AND s.ende > a.start)
+		WHERE s.start >= (" . $subquery . ")
+		ORDER BY s.start, s.ende
+		LIMIT ?;";
+
+		return $this->execQuery($sql, [
+			$max_length,
+			self::TYP_UNTERBRECHUNG,
+			Studierendenantragstatus_model::STATUS_CANCELLED,
+			$prestudent_id,
+			$studiensemester ?: $prestudent_id,
+			$max_length * $max_starters
+		]);
+	}
 }
diff --git a/public/js/components/Studierendenantrag/Form/Unterbrechung.js b/public/js/components/Studierendenantrag/Form/Unterbrechung.js
index a0e84af63..b0544dd3f 100644
--- a/public/js/components/Studierendenantrag/Form/Unterbrechung.js
+++ b/public/js/components/Studierendenantrag/Form/Unterbrechung.js
@@ -256,7 +256,7 @@ export default {
 							:id="'studierendenantrag-form-abmeldung-' + uuid + '-stsem'"
 							@input="currentWiedereinstieg = ''"
 							>
-							<option v-for="(stsem, index) in data.studiensemester" :key="index" :value="index">
+							<option v-for="(stsem, index) in data.studiensemester" :key="index" :value="index" :disabled="stsem.disabled">
 								{{stsem.studiensemester_kurzbz}}
 							</option>
 						</select>
@@ -280,7 +280,7 @@ export default {
 					</div>
 					<div v-else>
 						<select v-model="currentWiedereinstieg" class="form-select">
-							<option v-for="sem in data.studiensemester[stsem].wiedereinstieg" :key="sem.studiensemester_kurzbz" :value="sem.start">
+							<option v-for="sem in data.studiensemester[stsem].wiedereinstieg" :key="sem.studiensemester_kurzbz" :value="sem.start" :disabled="sem.disabled">
 								{{sem.studiensemester_kurzbz}}
 							</option>
 						</select>