diff --git a/gemma-core/src/main/java/ubic/gemma/model/expression/bioAssay/BioAssay.java b/gemma-core/src/main/java/ubic/gemma/model/expression/bioAssay/BioAssay.java
index 592e6e0bc3..76e8652227 100644
--- a/gemma-core/src/main/java/ubic/gemma/model/expression/bioAssay/BioAssay.java
+++ b/gemma-core/src/main/java/ubic/gemma/model/expression/bioAssay/BioAssay.java
@@ -29,6 +29,8 @@
 import javax.annotation.Nullable;
 import javax.persistence.Transient;
 import java.util.Date;
+import java.util.HashSet;
+import java.util.Set;
 
 /**
  * Represents the bringing together of a biomaterial with an assay of some sort (typically an expression assay). We
@@ -67,11 +69,16 @@ public class BioAssay extends AbstractDescribable implements SecuredChild {
     private BioMaterial sampleUsed;
 
     /**
-     * Accession for this assay.
+     * Primary accession for this assay, usually from GEO.
      */
     @Nullable
     private DatabaseEntry accession;
 
+    /**
+     * Other accessions for this assay.
+     */
+    private Set<DatabaseEntry> otherAccessions = new HashSet<>();
+
     /**
      * Indicates if the assay should be considered an outlier based on QC.
      * <p>
@@ -206,6 +213,25 @@ public void setAccession( @Nullable DatabaseEntry accession ) {
         this.accession = accession;
     }
 
+    @IndexedEmbedded
+    public Set<DatabaseEntry> getOtherAccessions() {
+        return otherAccessions;
+    }
+
+    public void setOtherAccessions( Set<DatabaseEntry> otherAccessions ) {
+        this.otherAccessions = otherAccessions;
+    }
+
+    @Transient
+    public Set<DatabaseEntry> getAllAccessions() {
+        Set<DatabaseEntry> allAccessions = new HashSet<>();
+        if ( this.accession != null ) {
+            allAccessions.add( this.accession );
+        }
+        allAccessions.addAll( this.otherAccessions );
+        return allAccessions;
+    }
+
     public ArrayDesign getArrayDesignUsed() {
         return this.arrayDesignUsed;
     }
diff --git a/gemma-core/src/main/java/ubic/gemma/model/expression/biomaterial/BioMaterial.java b/gemma-core/src/main/java/ubic/gemma/model/expression/biomaterial/BioMaterial.java
index 1535773304..25bcfe2d7a 100644
--- a/gemma-core/src/main/java/ubic/gemma/model/expression/biomaterial/BioMaterial.java
+++ b/gemma-core/src/main/java/ubic/gemma/model/expression/biomaterial/BioMaterial.java
@@ -58,8 +58,15 @@ public class BioMaterial extends AbstractDescribable implements SecuredChild {
     private Set<BioAssay> bioAssaysUsedIn = new HashSet<>();
     private Set<Treatment> treatments = new HashSet<>();
     private Set<Characteristic> characteristics = new HashSet<>();
+    /**
+     * Primary external accession for this biomaterial, if any.
+     */
     @Nullable
     private DatabaseEntry externalAccession;
+    /**
+     * Other external accessions that this biomaterial is associated with.
+     */
+    private Set<DatabaseEntry> otherExternalAccessions = new HashSet<>();
 
     @Override
     @DocumentId
@@ -147,6 +154,25 @@ public void setExternalAccession( @Nullable DatabaseEntry externalAccession ) {
         this.externalAccession = externalAccession;
     }
 
+    @IndexedEmbedded
+    public Set<DatabaseEntry> getOtherExternalAccessions() {
+        return otherExternalAccessions;
+    }
+
+    public void setOtherExternalAccessions( Set<DatabaseEntry> otherExternalAccessions ) {
+        this.otherExternalAccessions = otherExternalAccessions;
+    }
+
+
+    @Transient
+    public Set<DatabaseEntry> getAllExternalAccessions() {
+        Set<DatabaseEntry> allAccessions = new HashSet<>();
+        if ( this.externalAccession != null ) {
+            allAccessions.add( this.externalAccession );
+        }
+        allAccessions.addAll( this.otherExternalAccessions );
+        return allAccessions;
+    }
     /**
      * Obtain the values that this BioAssay is associated with for the experiment.
      */
diff --git a/gemma-core/src/main/java/ubic/gemma/model/expression/experiment/ExpressionExperiment.java b/gemma-core/src/main/java/ubic/gemma/model/expression/experiment/ExpressionExperiment.java
index 6137b69e4c..0646d221ff 100644
--- a/gemma-core/src/main/java/ubic/gemma/model/expression/experiment/ExpressionExperiment.java
+++ b/gemma-core/src/main/java/ubic/gemma/model/expression/experiment/ExpressionExperiment.java
@@ -31,6 +31,7 @@
 import ubic.gemma.model.genome.Taxon;
 
 import javax.annotation.Nullable;
+import javax.persistence.Transient;
 import java.util.HashSet;
 import java.util.Objects;
 import java.util.Set;
@@ -52,9 +53,17 @@ public static ExpressionExperiment newInstance() {
 
     public static final int MAX_NAME_LENGTH = 255;
 
+    /**
+     * Primary accession for this experiment, usually from GEO.
+     */
     @Nullable
     private DatabaseEntry accession;
 
+    /**
+     * Other accessions associated with this experiment.
+     */
+    private Set<DatabaseEntry> otherAccessions = new HashSet<>();
+
     /**
      * Type of batch effect detected or corrected for. See {@link BatchEffectType} enum for possible values.
      */
@@ -143,6 +152,21 @@ public DatabaseEntry getAccession() {
         return accession;
     }
 
+    @IndexedEmbedded
+    public Set<DatabaseEntry> getOtherAccessions() {
+        return otherAccessions;
+    }
+
+    @Transient
+    public Set<DatabaseEntry> getAllAccessions() {
+        Set<DatabaseEntry> allAccessions = new HashSet<>();
+        if ( this.accession != null ) {
+            allAccessions.add( this.accession );
+        }
+        allAccessions.addAll( this.otherAccessions );
+        return allAccessions;
+    }
+
     @Override
     @IndexedEmbedded
     public BibliographicReference getPrimaryPublication() {
@@ -260,6 +284,10 @@ public void setAccession( @Nullable DatabaseEntry accession ) {
         this.accession = accession;
     }
 
+    public void setOtherAccessions( Set<DatabaseEntry> otherAccessions ) {
+        this.otherAccessions = otherAccessions;
+    }
+
     public void setBatchConfound( @Nullable String batchConfound ) { // FIXME don't use a string for this
         this.batchConfound = batchConfound;
     }
diff --git a/gemma-core/src/main/java/ubic/gemma/persistence/service/expression/experiment/ExpressionExperimentDaoImpl.java b/gemma-core/src/main/java/ubic/gemma/persistence/service/expression/experiment/ExpressionExperimentDaoImpl.java
index fcb4e0a1a0..92ac8d09bf 100644
--- a/gemma-core/src/main/java/ubic/gemma/persistence/service/expression/experiment/ExpressionExperimentDaoImpl.java
+++ b/gemma-core/src/main/java/ubic/gemma/persistence/service/expression/experiment/ExpressionExperimentDaoImpl.java
@@ -2142,6 +2142,10 @@ public void thawLiter( final ExpressionExperiment expressionExperiment ) {
             thawDatabaseEntry( expressionExperiment.getAccession() );
         }
 
+        for ( DatabaseEntry de : expressionExperiment.getOtherAccessions() ) {
+            thawDatabaseEntry( de );
+        }
+
         if ( expressionExperiment.getMeanVarianceRelation() != null ) {
             Hibernate.initialize( expressionExperiment.getMeanVarianceRelation() );
         }
diff --git a/gemma-core/src/main/java/ubic/gemma/persistence/util/Thaws.java b/gemma-core/src/main/java/ubic/gemma/persistence/util/Thaws.java
index c8d1ed643d..94d6a0bed1 100644
--- a/gemma-core/src/main/java/ubic/gemma/persistence/util/Thaws.java
+++ b/gemma-core/src/main/java/ubic/gemma/persistence/util/Thaws.java
@@ -41,6 +41,9 @@ public static void thawBioAssayDimension( BioAssayDimension bioAssayDimension )
      * The corresponding biomaterial is also thawed with {@link #thawBioMaterial(BioMaterial)}.
      */
     public static void thawBioAssay( BioAssay ba ) {
+        for ( DatabaseEntry de : ba.getOtherAccessions() ) {
+            Thaws.thawDatabaseEntry( de );
+        }
         Hibernate.initialize( ba.getArrayDesignUsed() );
         Hibernate.initialize( ba.getArrayDesignUsed().getDesignProvider() );
         if ( ba.getOriginalPlatform() != null ) {
@@ -65,6 +68,9 @@ public static void thawBioMaterial( BioMaterial bm2 ) {
 
     private static void thawBioMaterial( BioMaterial bm2, boolean initializeBioAssaysUsedIn ) {
         visitBioMaterials( bm2, bm -> {
+            for ( DatabaseEntry de : bm.getOtherExternalAccessions() ) {
+                Thaws.thawDatabaseEntry( de );
+            }
             Hibernate.initialize( bm.getSourceTaxon() );
             Hibernate.initialize( bm.getTreatments() );
             for ( FactorValue fv : bm.getFactorValues() ) {
diff --git a/gemma-core/src/main/resources/ubic/gemma/model/analysis/Investigation.hbm.xml b/gemma-core/src/main/resources/ubic/gemma/model/analysis/Investigation.hbm.xml
index 3ea3454c61..7e02d6a32d 100644
--- a/gemma-core/src/main/resources/ubic/gemma/model/analysis/Investigation.hbm.xml
+++ b/gemma-core/src/main/resources/ubic/gemma/model/analysis/Investigation.hbm.xml
@@ -102,6 +102,12 @@
 					<!-- FIXME better to make non-unique to allow easier tracking of split experiments? -->
 					<column name="ACCESSION_FK" not-null="false" sql-type="BIGINT" unique="true"/>
 				</many-to-one>
+				<set name="otherAccessions" lazy="true" fetch="select" cascade="all-delete-orphan">
+					<key foreign-key="OTHER_ACCESSIONS_FKC">
+						<column name="EXPRESSION_EXPERIMENT_FK" sql-type="BIGINT"/>
+					</key>
+					<one-to-many class="ubic.gemma.model.common.description.DatabaseEntry"/>
+				</set>
 				<many-to-one name="experimentalDesign" class="ubic.gemma.model.expression.experiment.ExperimentalDesign"
 							 cascade="all" lazy="proxy" fetch="select">
 					<column name="EXPERIMENTAL_DESIGN_FK" not-null="false" sql-type="BIGINT" unique="true"/>
diff --git a/gemma-core/src/main/resources/ubic/gemma/model/expression/bioAssay/BioAssay.hbm.xml b/gemma-core/src/main/resources/ubic/gemma/model/expression/bioAssay/BioAssay.hbm.xml
index be8dea17b2..ea25333d00 100644
--- a/gemma-core/src/main/resources/ubic/gemma/model/expression/bioAssay/BioAssay.hbm.xml
+++ b/gemma-core/src/main/resources/ubic/gemma/model/expression/bioAssay/BioAssay.hbm.xml
@@ -64,6 +64,13 @@
                    lazy="false" fetch="join">
          <column name="ACCESSION_FK" not-null="false" sql-type="BIGINT" unique="true"/>
       </many-to-one>
+      <set name="otherAccessions" cascade="all-delete-orphan">
+         <cache usage="read-write"/>
+         <key foreign-key="OTHER_ACCESSIONS_FKC">
+            <column name="BIO_ASSAY_FK" sql-type="BIGINT"/>
+         </key>
+         <one-to-many class="ubic.gemma.model.common.description.DatabaseEntry"/>
+      </set>
       <!-- BioMaterial are in the second-level cached, so a select fetching is efficient -->
       <many-to-one name="sampleUsed" class="ubic.gemma.model.expression.biomaterial.BioMaterial"
                    lazy="false" fetch="select">
diff --git a/gemma-core/src/main/resources/ubic/gemma/model/expression/biomaterial/BioMaterial.hbm.xml b/gemma-core/src/main/resources/ubic/gemma/model/expression/biomaterial/BioMaterial.hbm.xml
index 8cabf04d18..a983001547 100644
--- a/gemma-core/src/main/resources/ubic/gemma/model/expression/biomaterial/BioMaterial.hbm.xml
+++ b/gemma-core/src/main/resources/ubic/gemma/model/expression/biomaterial/BioMaterial.hbm.xml
@@ -57,5 +57,12 @@
                    lazy="false" fetch="join">
          <column name="EXTERNAL_ACCESSION_FK" not-null="false" sql-type="BIGINT" unique="true"/>
       </many-to-one>
+      <set name="otherExternalAccessions" cascade="all-delete-orphan">
+         <cache usage="read-write"/>
+         <key foreign-key="OTHER_EXTERNAL_ACCESSION_BIO_MATERIAL_FKC">
+            <column name="BIO_MATERIAL_FK" sql-type="BIGINT"/>
+         </key>
+         <one-to-many class="ubic.gemma.model.common.description.DatabaseEntry"/>
+      </set>
    </class>
 </hibernate-mapping>
\ No newline at end of file