diff --git a/icu4c/source/i18n/region.cpp b/icu4c/source/i18n/region.cpp
index 9b4f3705aa9..67505035d45 100644
--- a/icu4c/source/i18n/region.cpp
+++ b/icu4c/source/i18n/region.cpp
@@ -1,6 +1,6 @@
 /*
 *******************************************************************************
-* Copyright (C) 2014, International Business Machines Corporation and
+* Copyright (C) 2014-2015, International Business Machines Corporation and
 * others. All Rights Reserved.
 *******************************************************************************
 *
@@ -232,13 +232,13 @@ void Region::loadRegionData(UErrorCode &status) {
 
     // Now fill in the special cases for WORLD, UNKNOWN, CONTINENTS, and GROUPINGS
     Region *r;
-	UnicodeString WORLD_ID_STRING(WORLD_ID);
+    UnicodeString WORLD_ID_STRING(WORLD_ID);
     r = (Region *) uhash_get(newRegionIDMap.getAlias(),(void *)&WORLD_ID_STRING);
     if ( r ) {
         r->type = URGN_WORLD;
     }
 
-	UnicodeString UNKNOWN_REGION_ID_STRING(UNKNOWN_REGION_ID);
+    UnicodeString UNKNOWN_REGION_ID_STRING(UNKNOWN_REGION_ID);
     r = (Region *) uhash_get(newRegionIDMap.getAlias(),(void *)&UNKNOWN_REGION_ID_STRING);
     if ( r ) {
         r->type = URGN_UNKNOWN;
@@ -261,7 +261,7 @@ void Region::loadRegionData(UErrorCode &status) {
     // Special case: The region code "QO" (Outlying Oceania) is a subcontinent code added by CLDR
     // even though it looks like a territory code.  Need to handle it here.
 
-	UnicodeString OUTLYING_OCEANIA_REGION_ID_STRING(OUTLYING_OCEANIA_REGION_ID);
+    UnicodeString OUTLYING_OCEANIA_REGION_ID_STRING(OUTLYING_OCEANIA_REGION_ID);
     r = (Region *) uhash_get(newRegionIDMap.getAlias(),(void *)&OUTLYING_OCEANIA_REGION_ID_STRING);
     if ( r ) {
         r->type = URGN_SUBCONTINENT;
@@ -373,6 +373,7 @@ Region::~Region () {
 
 /**
  * Returns true if the two regions are equal.
+ * Per PMC, just use pointer compare, since we have at most one instance of each Region.
  */
 UBool
 Region::operator==(const Region &that) const {
@@ -381,6 +382,7 @@ Region::operator==(const Region &that) const {
 
 /**
  * Returns true if the two regions are NOT equal; that is, if operator ==() returns false.
+ * Per PMC, just use pointer compare, since we have at most one instance of each Region.
  */
 UBool
 Region::operator!=(const Region &that) const {
@@ -419,7 +421,7 @@ Region::getInstance(const char *region_code, UErrorCode &status) {
     }
 
     if ( r->type == URGN_DEPRECATED && r->preferredValues->size() == 1) {
-        StringEnumeration *pv = r->getPreferredValues();
+        StringEnumeration *pv = r->getPreferredValues(status);
         pv->reset(status);
         const UnicodeString *ustr = pv->snext(status);
         r = (Region *)uhash_get(regionIDMap,(void *)ustr);
@@ -468,7 +470,7 @@ Region::getInstance (int32_t code, UErrorCode &status) {
     }
 
     if ( r->type == URGN_DEPRECATED && r->preferredValues->size() == 1) {
-        StringEnumeration *pv = r->getPreferredValues();
+        StringEnumeration *pv = r->getPreferredValues(status);
         pv->reset(status);
         const UnicodeString *ustr = pv->snext(status);
         r = (Region *)uhash_get(regionIDMap,(void *)ustr);
@@ -483,9 +485,8 @@ Region::getInstance (int32_t code, UErrorCode &status) {
  * Returns an enumeration over the IDs of all known regions that match the given type.
  */
 StringEnumeration* U_EXPORT2
-Region::getAvailable(URegionType type) {
-    UErrorCode status = U_ZERO_ERROR;
-    umtx_initOnce(gRegionDataInitOnce, &loadRegionData, status);
+Region::getAvailable(URegionType type, UErrorCode &status) {
+    umtx_initOnce(gRegionDataInitOnce, &loadRegionData, status); // returns immediately if U_FAILURE(status)
     if (U_FAILURE(status)) {
         return NULL;
     }
@@ -519,11 +520,7 @@ Region::getContainingRegion(URegionType type) const {
         return NULL;
     }
 
-    if ( containingRegion->type == type ) {
-        return containingRegion;
-    } else {
-        return containingRegion->getContainingRegion(type);
-    }
+    return ( containingRegion->type == type )? containingRegion: containingRegion->getContainingRegion(type);
 }
 
 /**
@@ -535,9 +532,11 @@ Region::getContainingRegion(URegionType type) const {
  * and "155" (Western Europe).
  */
 StringEnumeration*
-Region::getContainedRegions() const {
-    UErrorCode status = U_ZERO_ERROR;
-    umtx_initOnce(gRegionDataInitOnce, &loadRegionData, status);
+Region::getContainedRegions(UErrorCode &status) const {
+    umtx_initOnce(gRegionDataInitOnce, &loadRegionData, status); // returns immediately if U_FAILURE(status)
+    if (U_FAILURE(status)) {
+        return NULL;
+    }
     return new RegionNameEnumeration(containedRegions,status);
 }
 
@@ -548,16 +547,15 @@ Region::getContainedRegions() const {
  * "URGN_TERRITORY" returns a set containing all the territories in Europe ( "FR" (France) - "IT" (Italy) - "DE" (Germany) etc. )
  */
 StringEnumeration*
-Region::getContainedRegions( URegionType type ) const {
-    UErrorCode status = U_ZERO_ERROR;
-    umtx_initOnce(gRegionDataInitOnce, &loadRegionData, status);
+Region::getContainedRegions( URegionType type, UErrorCode &status ) const {
+    umtx_initOnce(gRegionDataInitOnce, &loadRegionData, status); // returns immediately if U_FAILURE(status)
     if (U_FAILURE(status)) {
         return NULL;
     }
 
     UVector *result = new UVector(NULL, uhash_compareChars, status);
 
-    StringEnumeration *cr = getContainedRegions();
+    StringEnumeration *cr = getContainedRegions(status);
 
     for ( int32_t i = 0 ; i < cr->count(status) ; i++ ) {
         const char *id = cr->next(NULL,status);
@@ -565,7 +563,7 @@ Region::getContainedRegions( URegionType type ) const {
         if ( r->getType() == type ) {
             result->addElement((void *)&r->idStr,status);
         } else {
-            StringEnumeration *children = r->getContainedRegions(type);
+            StringEnumeration *children = r->getContainedRegions(type, status);
             for ( int32_t j = 0 ; j < children->count(status) ; j++ ) {
                 const char *id2 = children->next(NULL,status);
                 const Region *r2 = Region::getInstance(id2,status);
@@ -612,14 +610,12 @@ Region::contains(const Region &other) const {
  * "SU" (Soviet Union) would return a list of the regions containing "RU" (Russia), "AM" (Armenia), "AZ" (Azerbaijan), etc...
  */
 StringEnumeration*
-Region::getPreferredValues() const {
-    UErrorCode status = U_ZERO_ERROR;
-    umtx_initOnce(gRegionDataInitOnce, &loadRegionData, status);
-    if ( type == URGN_DEPRECATED ) {
-        return new RegionNameEnumeration(preferredValues,status);
-    } else {
+Region::getPreferredValues(UErrorCode &status) const {
+    umtx_initOnce(gRegionDataInitOnce, &loadRegionData, status); // returns immediately if U_FAILURE(status)
+    if (U_FAILURE(status) ||  type != URGN_DEPRECATED) {
         return NULL;
     }
+    return new RegionNameEnumeration(preferredValues,status);
 }
 
 
diff --git a/icu4c/source/i18n/unicode/region.h b/icu4c/source/i18n/unicode/region.h
index c33681e7e79..cb75234bf9b 100644
--- a/icu4c/source/i18n/unicode/region.h
+++ b/icu4c/source/i18n/unicode/region.h
@@ -1,6 +1,6 @@
 /*
  *******************************************************************************
- * Copyright (C) 2014, International Business Machines Corporation and others.
+ * Copyright (C) 2014-2015, International Business Machines Corporation and others.
  * All Rights Reserved.
  *******************************************************************************
  */
@@ -104,9 +104,9 @@ public:
 #ifndef U_HIDE_DRAFT_API
     /**
      * Returns an enumeration over the IDs of all known regions that match the given type.
-     * @draft ICU 51
+     * @draft ICU 55
      */
-    static StringEnumeration* U_EXPORT2 getAvailable(URegionType type);
+    static StringEnumeration* U_EXPORT2 getAvailable(URegionType type, UErrorCode &status);
 #endif /* U_HIDE_DRAFT_API */
    
     /**
@@ -135,18 +135,18 @@ public:
      * any sub-regions. For example, calling this method with region "150" (Europe) returns an enumeration containing
      * the various sub regions of Europe - "039" (Southern Europe) - "151" (Eastern Europe) - "154" (Northern Europe)
      * and "155" (Western Europe).
-     * @draft ICU 51 
+     * @draft ICU 55 
      */
-    StringEnumeration* getContainedRegions() const;
+    StringEnumeration* getContainedRegions(UErrorCode &status) const;
 
     /**
      * Returns an enumeration over the IDs of all the regions that are children of this region anywhere in the region
      * hierarchy and match the given type.  This API may return an empty enumeration if this region doesn't have any
      * sub-regions that match the given type. For example, calling this method with region "150" (Europe) and type
      * "URGN_TERRITORY" returns a set containing all the territories in Europe ( "FR" (France) - "IT" (Italy) - "DE" (Germany) etc. )
-     * @draft ICU 51 
+     * @draft ICU 55 
      */
-    StringEnumeration* getContainedRegions( URegionType type ) const;
+    StringEnumeration* getContainedRegions( URegionType type, UErrorCode &status ) const;
 #endif /* U_HIDE_DRAFT_API */
  
     /**
@@ -160,9 +160,9 @@ public:
      * For deprecated regions, return an enumeration over the IDs of the regions that are the preferred replacement
      * regions for this region.  Returns null for a non-deprecated region.  For example, calling this method with region
      * "SU" (Soviet Union) would return a list of the regions containing "RU" (Russia), "AM" (Armenia), "AZ" (Azerbaijan), etc...
-     * @draft ICU 51 
+     * @draft ICU 55 
      */
-    StringEnumeration* getPreferredValues() const;
+    StringEnumeration* getPreferredValues(UErrorCode &status) const;
 #endif /* U_HIDE_DRAFT_API */
 
     /**
diff --git a/icu4c/source/i18n/uregion.cpp b/icu4c/source/i18n/uregion.cpp
index 5e4ba4ca528..58bd9d0a0cc 100644
--- a/icu4c/source/i18n/uregion.cpp
+++ b/icu4c/source/i18n/uregion.cpp
@@ -1,6 +1,6 @@
 /*
 *****************************************************************************************
-* Copyright (C) 2013, International Business Machines Corporation and others.
+* Copyright (C) 2013-2015, International Business Machines Corporation and others.
 * All Rights Reserved.
 *****************************************************************************************
 */
@@ -12,6 +12,7 @@
 #include "unicode/uregion.h"
 #include "unicode/region.h"
 #include "unicode/uenum.h"
+#include "unicode/strenum.h"
 
 U_NAMESPACE_USE
 
@@ -33,7 +34,8 @@ uregion_getRegionFromNumericCode (int32_t code, UErrorCode *status)
 U_CAPI UEnumeration* U_EXPORT2
 uregion_getAvailable(URegionType type, UErrorCode *status)
 {
-    return uenum_openFromStringEnumeration( Region::getAvailable(type), status );
+    StringEnumeration* strenum = Region::getAvailable(type, *status);
+    return uenum_openFromStringEnumeration( strenum, status );
 }
 
 
@@ -61,14 +63,16 @@ uregion_getContainingRegionOfType(const URegion* uregion, URegionType type)
 U_CAPI UEnumeration* U_EXPORT2
 uregion_getContainedRegions(const URegion* uregion, UErrorCode *status)
 {
-    return uenum_openFromStringEnumeration( ((Region*)uregion)->getContainedRegions(), status);
+    StringEnumeration* strenum = ((Region*)uregion)->getContainedRegions(*status);
+    return uenum_openFromStringEnumeration( strenum, status);
 }
 
 
 U_CAPI UEnumeration* U_EXPORT2
 uregion_getContainedRegionsOfType(const URegion* uregion, URegionType type, UErrorCode *status)
 {
-    return uenum_openFromStringEnumeration( ((Region*)uregion)->getContainedRegions(type), status);
+    StringEnumeration* strenum = ((Region*)uregion)->getContainedRegions(type, *status);
+    return uenum_openFromStringEnumeration( strenum, status);
 }
 
 
@@ -82,7 +86,8 @@ uregion_contains(const URegion* uregion, const URegion* otherRegion)
 U_CAPI UEnumeration* U_EXPORT2
 uregion_getPreferredValues(const URegion* uregion, UErrorCode *status)
 {
-    return uenum_openFromStringEnumeration( ((Region*)uregion)->getPreferredValues(), status);
+    StringEnumeration* strenum = ((Region*)uregion)->getPreferredValues(*status);
+    return uenum_openFromStringEnumeration( strenum, status);
 }
 
 
diff --git a/icu4c/source/test/intltest/regiontst.cpp b/icu4c/source/test/intltest/regiontst.cpp
index d2da87fec67..d8ce8bb661e 100644
--- a/icu4c/source/test/intltest/regiontst.cpp
+++ b/icu4c/source/test/intltest/regiontst.cpp
@@ -1,6 +1,6 @@
 /***********************************************************************
  * COPYRIGHT: 
- * Copyright (c) 2013-2014, International Business Machines Corporation
+ * Copyright (c) 2013-2015, International Business Machines Corporation
  * and others. All Rights Reserved.
  ***********************************************************************/
  
@@ -499,7 +499,11 @@ void RegionTest::TestGetContainedRegions() {
             if (r->getType() == URGN_GROUPING) {
                 continue;
             }
-            StringEnumeration *containedRegions = r->getContainedRegions();
+            StringEnumeration *containedRegions = r->getContainedRegions(status);
+            if (U_FAILURE(status)) {
+              errln("%s->getContainedRegions(status) failed: %s", r->getRegionCode(), u_errorName(status));
+              continue;
+            }
             for ( int32_t i = 0 ; i < containedRegions->count(status); i++ ) {
                 const char *crID = containedRegions->next(NULL,status);
                 const Region *cr = Region::getInstance(crID,status);
@@ -526,7 +530,11 @@ void RegionTest::TestGetContainedRegionsWithType() {
             if (r->getType() != URGN_CONTINENT) {
                 continue;
             }
-            StringEnumeration *containedRegions = r->getContainedRegions(URGN_TERRITORY);
+            StringEnumeration *containedRegions = r->getContainedRegions(URGN_TERRITORY, status);
+            if (U_FAILURE(status)) {
+              errln("%s->getContainedRegions(URGN_TERRITORY, status) failed: %s", r->getRegionCode(), u_errorName(status));
+              continue;
+            }
             for ( int32_t j = 0 ; j < containedRegions->count(status); j++ ) {
                 const char *crID = containedRegions->next(NULL,status);
                 const Region *cr = Region::getInstance(crID,status);
@@ -608,7 +616,11 @@ void RegionTest::TestGetPreferredValues() {
         UErrorCode status = U_ZERO_ERROR;
         const Region *r = Region::getInstance(data[0],status);
         if (r) {
-            StringEnumeration *preferredValues = r->getPreferredValues();
+            StringEnumeration *preferredValues = r->getPreferredValues(status);
+            if (U_FAILURE(status)) {
+              errln("%s->getPreferredValues(status) failed: %s", r->getRegionCode(), u_errorName(status));
+              continue;
+            }
             for ( int i = 1 ; data[i] ; i++ ) {
                 UBool found = FALSE;
                 preferredValues->reset(status);
@@ -653,13 +665,21 @@ void RegionTest::TestAvailableTerritories() {
     // Test to make sure that the set of territories contained in World and the set of all available
     // territories are one and the same.
     UErrorCode status = U_ZERO_ERROR;
-    StringEnumeration *availableTerritories = Region::getAvailable(URGN_TERRITORY);
+    StringEnumeration *availableTerritories = Region::getAvailable(URGN_TERRITORY, status);
+    if (U_FAILURE(status)) {
+        errln("Region::getAvailable(URGN_TERRITORY,status) failed: %s", u_errorName(status));
+        return;
+    }
     const Region *world = Region::getInstance("001",status);
     if (U_FAILURE(status)) {
         dataerrln("Region::getInstance(\"001\",status) failed: %s", u_errorName(status));
         return;
     }
-    StringEnumeration *containedInWorld = world->getContainedRegions(URGN_TERRITORY);
+    StringEnumeration *containedInWorld = world->getContainedRegions(URGN_TERRITORY, status);
+    if (U_FAILURE(status)) {
+        errln("world->getContainedRegions(URGN_TERRITORY, status) failed: %s", u_errorName(status));
+        return;
+    }
     if ( !availableTerritories || !containedInWorld || *availableTerritories != *containedInWorld ) {
         char availableTerritoriesString[1024] = "";
         char containedInWorldString[1024] = "";
@@ -697,7 +717,11 @@ void RegionTest::TestNoContainedRegions(void) {
       dataerrln("Fail called to Region::getInstance(\"BM\", status) - %s", u_errorName(status));
       return;
   }
-  StringEnumeration *containedRegions = region->getContainedRegions();
+  StringEnumeration *containedRegions = region->getContainedRegions(status);
+  if (U_FAILURE(status)) {
+      errln("%s->getContainedRegions(status) failed: %s", region->getRegionCode(), u_errorName(status));
+      return;
+  }
   const char *emptyStr = containedRegions->next(NULL, status);
   if (U_FAILURE(status)||(emptyStr!=NULL)) {
     errln("Error, 'BM' should have no subregions, but returned str=%p, err=%s\n", emptyStr, u_errorName(status));