diff --git a/src/FhirOperationDefinitionGen.Tests/FhirOperationDefinitionGen.Tests.csproj b/src/FhirOperationDefinitionGen.Tests/FhirOperationDefinitionGen.Tests.csproj
index 70d0a55..ddd901e 100644
--- a/src/FhirOperationDefinitionGen.Tests/FhirOperationDefinitionGen.Tests.csproj
+++ b/src/FhirOperationDefinitionGen.Tests/FhirOperationDefinitionGen.Tests.csproj
@@ -11,7 +11,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Hl7.Fhir.R4" Version="5.7.0" />
+    <PackageReference Include="Hl7.Fhir.R4" Version="6.1.0" />
     <PackageReference Include="FluentAssertions" Version="6.12.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.1" />
     <PackageReference Include="Verify.XUnit" Version="20.8.2" />
diff --git a/src/FhirOperationDefinitionGen/FhirOperationDefinitionGen.csproj b/src/FhirOperationDefinitionGen/FhirOperationDefinitionGen.csproj
index 21ac7bd..86e329d 100644
--- a/src/FhirOperationDefinitionGen/FhirOperationDefinitionGen.csproj
+++ b/src/FhirOperationDefinitionGen/FhirOperationDefinitionGen.csproj
@@ -10,7 +10,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.9.2" PrivateAssets="all" />
     <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
-    <PackageReference Include="Hl7.Fhir.R4" Version="5.7.0" PrivateAssets="all"
+    <PackageReference Include="Hl7.Fhir.R4" Version="6.1.0" PrivateAssets="all"
       GeneratePathProperty="true" />
     <PackageReference Include="Hl7.Fhir.Base" Version="5.7.0" PrivateAssets="all"
       GeneratePathProperty="true" />
diff --git a/src/FhirParametersGenerator.Benchmark/FhirParametersGenerator.Benchmark.csproj b/src/FhirParametersGenerator.Benchmark/FhirParametersGenerator.Benchmark.csproj
index e48024b..926ee60 100644
--- a/src/FhirParametersGenerator.Benchmark/FhirParametersGenerator.Benchmark.csproj
+++ b/src/FhirParametersGenerator.Benchmark/FhirParametersGenerator.Benchmark.csproj
@@ -11,7 +11,7 @@
 
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" Version="0.13.12" />
-    <PackageReference Include="Hl7.Fhir.R4" Version="5.7.0" />
+    <PackageReference Include="Hl7.Fhir.R4" Version="6.1.0" />
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.9.2" PrivateAssets="all" />
     <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
   </ItemGroup>
diff --git a/src/FhirParametersGenerator.Demo/FhirParametersGenerator.Demo.csproj b/src/FhirParametersGenerator.Demo/FhirParametersGenerator.Demo.csproj
index 2926c95..3b42637 100644
--- a/src/FhirParametersGenerator.Demo/FhirParametersGenerator.Demo.csproj
+++ b/src/FhirParametersGenerator.Demo/FhirParametersGenerator.Demo.csproj
@@ -13,7 +13,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Hl7.Fhir.R4" Version="5.7.0" />
+    <PackageReference Include="Hl7.Fhir.R4" Version="6.1.0" />
     <ProjectReference
       Include="..\FhirParametersGenerator.Attributes\FhirParametersGenerator.Attributes.csproj" />
   </ItemGroup>
diff --git a/src/FhirParametersGenerator.Tests/FhirParametersGenerator.Tests.csproj b/src/FhirParametersGenerator.Tests/FhirParametersGenerator.Tests.csproj
index 0adb136..195ec1b 100644
--- a/src/FhirParametersGenerator.Tests/FhirParametersGenerator.Tests.csproj
+++ b/src/FhirParametersGenerator.Tests/FhirParametersGenerator.Tests.csproj
@@ -12,7 +12,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Hl7.Fhir.R4" Version="5.7.0" />
+    <PackageReference Include="Hl7.Fhir.R4" Version="6.1.0" />
     <PackageReference Include="FluentAssertions" Version="6.12.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
     <PackageReference Include="Verify.XUnit" Version="19.14.1" />