diff --git a/include/Dialect/Pulse/Utils/Utils.h b/include/Dialect/Pulse/Utils/Utils.h
index 2cdea100c..ec2cf8e9e 100644
--- a/include/Dialect/Pulse/Utils/Utils.h
+++ b/include/Dialect/Pulse/Utils/Utils.h
@@ -82,4 +82,21 @@ MixFrameOp getMixFrameOp(PulseOpTy pulseOp,
   return mixFrameOp;
 }
 
+template <typename PulseOpTy>
+llvm::StringRef getMixFrameName(PulseOpTy pulseOp, SequenceOp sequenceOp) {
+
+  auto frameArgIndex =
+      pulseOp.getTarget().template cast<BlockArgument>().getArgNumber();
+
+  assert(sequenceOp->hasAttrOfType<ArrayAttr>("pulse.args") and
+         "no pulse.args found for the pulse cal sequence.");
+
+  auto argAttr = sequenceOp->getAttrOfType<ArrayAttr>("pulse.args");
+
+  llvm::StringRef frameName =
+      argAttr[frameArgIndex].template dyn_cast<StringAttr>().getValue();
+
+  return frameName;
+}
+
 } // end namespace mlir::pulse
diff --git a/lib/Conversion/QUIRToPulse/LoadPulseCals.cpp b/lib/Conversion/QUIRToPulse/LoadPulseCals.cpp
index 0ae5b2fee..e6d7d33b4 100644
--- a/lib/Conversion/QUIRToPulse/LoadPulseCals.cpp
+++ b/lib/Conversion/QUIRToPulse/LoadPulseCals.cpp
@@ -22,6 +22,7 @@
 
 #include "Dialect/Pulse/IR/PulseDialect.h"
 #include "Dialect/Pulse/IR/PulseOps.h"
+#include "Dialect/QCS/IR/QCSOps.h"
 #include "Dialect/QUIR/IR/QUIROps.h"
 #include "Dialect/QUIR/IR/QUIRTraits.h"
 #include "Dialect/QUIR/Utils/Utils.h"
@@ -145,7 +146,9 @@ void LoadPulseCalsPass::loadPulseCals(CallCircuitOp callCircuitOp,
       loadPulseCals(castOp, callCircuitOp, funcOp);
     else if (auto castOp = dyn_cast<mlir::quir::ResetQubitOp>(op))
       loadPulseCals(castOp, callCircuitOp, funcOp);
-    else {
+    else if (isa<mlir::qcs::DelayCyclesOp>(op)) {
+      // no pulse call to load for a delay cycles op
+    } else {
       LLVM_DEBUG(llvm::dbgs() << "no pulse cal loading needed for " << op);
       assert((!op->hasTrait<mlir::quir::UnitaryOp>() and
               !op->hasTrait<mlir::quir::CPTPOp>()) &&
diff --git a/lib/Conversion/QUIRToPulse/QUIRToPulse.cpp b/lib/Conversion/QUIRToPulse/QUIRToPulse.cpp
index 6bfd4e7b3..b01fd5d9a 100644
--- a/lib/Conversion/QUIRToPulse/QUIRToPulse.cpp
+++ b/lib/Conversion/QUIRToPulse/QUIRToPulse.cpp
@@ -110,6 +110,11 @@ void QUIRToPulsePass::runOnOperation() {
   // erase circuit ops
   moduleOp->walk([&](CircuitOp circOp) { circOp->erase(); });
 
+  // Remove all arguments from synchronization ops
+  moduleOp->walk([](qcs::SynchronizeOp synchOp) {
+    synchOp.getQubitsMutable().assign(ValueRange({}));
+  });
+
   // erase qubit ops and constant angle ops
   moduleOp->walk([&](Operation *op) {
     if (isa<mlir::quir::DeclareQubitOp>(op))
@@ -216,6 +221,11 @@ QUIRToPulsePass::convertCircuitToSequence(CallCircuitOp &callCircuitOp,
         PulseOpSchedulingInterface::setDuration(pulseCalCallSequenceOp,
                                                 durValue);
       }
+    } else if (isa<qcs::DelayCyclesOp>(quirOp)) {
+      // a qcs.delay_cycles may be inserted into a quir.circuit and should be
+      // placed outside of the sequence at the call point
+      auto *newDelayCyclesOp = builder.clone(*quirOp);
+      newDelayCyclesOp->moveAfter(callCircuitOp);
     } else
       assert(((isa<quir::ConstantOp>(quirOp) or isa<quir::ReturnOp>(quirOp) or
                isa<quir::CircuitOp>(quirOp))) &&
@@ -229,7 +239,7 @@ QUIRToPulsePass::convertCircuitToSequence(CallCircuitOp &callCircuitOp,
                 convertedPulseSequenceOpReturnTypes.size()));
   convertedPulseSequenceOp.setType(newFuncType);
   entryBuilder.create<mlir::pulse::ReturnOp>(
-      convertedPulseSequenceOp.back().back().getLoc(),
+      convertedPulseSequenceOp.getLoc(),
       mlir::ValueRange{convertedPulseSequenceOpReturnValues});
   convertedPulseSequenceOp->moveBefore(mainFunc);
 
@@ -239,7 +249,6 @@ QUIRToPulsePass::convertCircuitToSequence(CallCircuitOp &callCircuitOp,
                                                   convertedPulseSequenceOp,
                                                   convertedPulseSequenceOpArgs);
   convertedPulseCallSequenceOp->moveAfter(callCircuitOp);
-
   return convertedPulseCallSequenceOp;
 }
 
diff --git a/lib/Frontend/OpenQASM3/QUIRGenQASM3Visitor.cpp b/lib/Frontend/OpenQASM3/QUIRGenQASM3Visitor.cpp
index fe15ba242..bb7f38624 100644
--- a/lib/Frontend/OpenQASM3/QUIRGenQASM3Visitor.cpp
+++ b/lib/Frontend/OpenQASM3/QUIRGenQASM3Visitor.cpp
@@ -540,11 +540,10 @@ void QUIRGenQASM3Visitor::visit(const ASTSwitchStatementNode *node) {
   SmallVector<uint32_t> caseValues;
   for (auto const &[key, caseStatement] : node->GetCaseStatementsMap())
     caseValues.push_back(caseStatement->GetCaseIndex());
-  if (!caseValues.empty())
-    caseValuesAttr = DenseIntElementsAttr::get(
-        VectorType::get(static_cast<int64_t>(caseValues.size()),
-                        builder.getIntegerType(32)),
-        caseValues);
+  caseValuesAttr = DenseIntElementsAttr::get(
+      VectorType::get(static_cast<int64_t>(caseValues.size()),
+                      builder.getIntegerType(32)),
+      caseValues);
 
   auto caseOperands = node->GetCaseStatementsMap();
 
diff --git a/releasenotes/notes/default-only-switch-64bb951256d7d2b5.yaml b/releasenotes/notes/default-only-switch-64bb951256d7d2b5.yaml
new file mode 100644
index 000000000..08ea6303e
--- /dev/null
+++ b/releasenotes/notes/default-only-switch-64bb951256d7d2b5.yaml
@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Switch statements with only a default region will now correctly compile.
diff --git a/test/Frontend/OpenQASM3/switch-default-only.qasm3 b/test/Frontend/OpenQASM3/switch-default-only.qasm3
new file mode 100644
index 000000000..79fa5a729
--- /dev/null
+++ b/test/Frontend/OpenQASM3/switch-default-only.qasm3
@@ -0,0 +1,32 @@
+OPENQASM 3.0;
+// RUN: qss-compiler -X=qasm --emit=ast-pretty %s | FileCheck %s --match-full-lines --check-prefix AST-PRETTY
+// RUN: qss-compiler -X=qasm --emit=mlir %s --enable-circuits-from-qasm=false| FileCheck %s --match-full-lines --check-prefixes MLIR
+// RUN: qss-compiler -X=qasm --emit=mlir %s --enable-circuits-from-qasm | FileCheck %s --match-full-lines --check-prefixes MLIR
+
+//
+// This code is part of Qiskit.
+//
+// (C) Copyright IBM 2023, 2024.
+//
+// This code is licensed under the Apache License, Version 2.0 with LLVM
+// Exceptions. You may obtain a copy of this license in the LICENSE.txt
+// file in the root directory of this source tree.
+//
+// Any modifications or derivative works of this code must retain this
+// copyright notice, and modified files need to carry a notice indicating
+// that they have been altered from the originals.
+
+int i = 15;
+qubit $0;
+// MLIR: quir.switch %{{.*}}{
+// MLIR-NEXT: }[]
+// AST-PRETTY: SwitchStatementNode(SwitchQuantity(name=i, type=ASTTypeIdentifier),
+switch (i) {
+    // AST-PRETTY:statements=[
+    // AST-PRETTY:],
+    // AST-PRETTY:default statement=[
+    // AST-PRETTY:])
+    default: {
+    }
+    break;
+}