diff --git a/src/AceEditor/madie-ace-editor.tsx b/src/AceEditor/madie-ace-editor.tsx
index 2eb17a9c..a81a9078 100644
--- a/src/AceEditor/madie-ace-editor.tsx
+++ b/src/AceEditor/madie-ace-editor.tsx
@@ -20,6 +20,7 @@ import "./madie-custom.css";
 import { ParsedCql, Statement } from "../model/ParsedCql";
 import {
   CqlMetaData,
+  Parameter,
   ValueSetForSearch,
 } from "../api/useTerminologyServiceApi";
 import { Definition } from "../CqlBuilderPanel/definitionsSection/definitionBuilder/DefinitionBuilder";
@@ -29,6 +30,7 @@ export interface EditorPropsType {
   value: string;
   onChange?: (value: string) => void;
   handleApplyCode?: (code: string) => void;
+  handleApplyParameter?: (parameter: Parameter) => void;
   handleApplyValueSet?: (vs: ValueSetForSearch) => void;
   handleApplyDefinition?: (def: Definition) => void;
   handleDefinitionEdit?: (lib: SelectedLibrary, def: Definition) => void;
diff --git a/src/CqlBuilderPanel/CqlBuilderPanel.test.tsx b/src/CqlBuilderPanel/CqlBuilderPanel.test.tsx
index 3f219d53..8bb107c0 100644
--- a/src/CqlBuilderPanel/CqlBuilderPanel.test.tsx
+++ b/src/CqlBuilderPanel/CqlBuilderPanel.test.tsx
@@ -662,7 +662,7 @@ describe("CqlBuilderPanel", () => {
     expect(parameterTab).not.toBeEnabled();
   });
 
-  it("Parameters works", async () => {
+  it("Parameters clear works", async () => {
     useFeatureFlags.mockImplementationOnce(() => ({
       CQLBuilderIncludes: true,
       QDMValueSetSearch: true,
@@ -725,4 +725,146 @@ describe("CqlBuilderPanel", () => {
       expect(aceEditor.value).toContain("");
     });
   });
+  it("Parameters apply works and clears input fields", async () => {
+    useFeatureFlags.mockImplementationOnce(() => ({
+      CQLBuilderIncludes: true,
+      QDMValueSetSearch: true,
+      CQLBuilderDefinitions: true,
+      qdmCodeSearch: true,
+      CQLBuilderParameters: true,
+    }));
+    mockedAxios.put.mockResolvedValue({
+      data: mockCqlBuilderLookUpData,
+    });
+
+    const applyParameter = jest.fn();
+    applyParameter.mockReturnValue("success");
+    const copiedProps = { ...props, handleApplyParameter: applyParameter };
+    let result = render(<CqlBuilderPanel {...copiedProps} />);
+    const parameterTab = await screen.queryByText("Parameters");
+    expect(parameterTab).toBeInTheDocument();
+    userEvent.click(screen.getByRole("tab", { name: "Parameters" }));
+    expect(screen.getByTestId("cql-editor-parameters")).toBeInTheDocument();
+
+    await userEvent.click(screen.getByTestId("saved-parameters-tab"));
+
+    await waitFor(() => {
+      expect(screen.getByTestId("saved-parameters-tab")).toHaveAttribute(
+        "aria-selected",
+        "true"
+      );
+    });
+    expect(screen.getByTestId("saved-parameters")).toBeInTheDocument();
+    // switch back
+    await userEvent.click(screen.getByTestId("parameter-tab"));
+    await waitFor(() => {
+      expect(screen.getByTestId("parameter-tab")).toHaveAttribute(
+        "aria-selected",
+        "true"
+      );
+    });
+    // write some stuff in parameter name
+    const parameterInput = screen.getByTestId(
+      "parameter-name-input"
+    ) as HTMLInputElement;
+    userEvent.type(parameterInput, "SomeText");
+    expect(parameterInput.value).toBe("SomeText");
+    // we now see expression edtior
+    const editor = screen.getByTestId(
+      "terminology-section-sub-header-content-Expression Editor"
+    );
+    expect(editor).toBeVisible();
+
+    //paste into editor, check it's there
+    const editorValue = "Some more Text";
+    let aceEditor: any = await result.container.querySelector(
+      "#ace-editor-wrapper textarea"
+    );
+    userEvent.paste(aceEditor, editorValue);
+    aceEditor = await result.container.querySelector(
+      "#ace-editor-wrapper textarea"
+    );
+    expect(aceEditor.value).toContain(editorValue);
+    // check that clear does anything
+    userEvent.click(getByTestId("apply-parameter-btn"));
+    await waitFor(() => {
+      expect(applyParameter).toHaveBeenCalledWith({
+        expression: "Some more Text",
+        parameterName: "SomeText",
+      });
+      expect(parameterInput.value).toBe("");
+      expect(aceEditor.value).toContain("");
+    });
+  });
+  it("Parameters apply did not work, fields did not get updated", async () => {
+    useFeatureFlags.mockImplementationOnce(() => ({
+      CQLBuilderIncludes: true,
+      QDMValueSetSearch: true,
+      CQLBuilderDefinitions: true,
+      qdmCodeSearch: true,
+      CQLBuilderParameters: true,
+    }));
+    mockedAxios.put.mockResolvedValue({
+      data: mockCqlBuilderLookUpData,
+    });
+
+    const applyParameter = jest.fn();
+    applyParameter.mockReturnValue("failure");
+    const copiedProps = { ...props, handleApplyParameter: applyParameter };
+    let result = render(<CqlBuilderPanel {...copiedProps} />);
+    const parameterTab = await screen.queryByText("Parameters");
+    expect(parameterTab).toBeInTheDocument();
+    userEvent.click(screen.getByRole("tab", { name: "Parameters" }));
+    expect(screen.getByTestId("cql-editor-parameters")).toBeInTheDocument();
+
+    await userEvent.click(screen.getByTestId("saved-parameters-tab"));
+
+    await waitFor(() => {
+      expect(screen.getByTestId("saved-parameters-tab")).toHaveAttribute(
+        "aria-selected",
+        "true"
+      );
+    });
+    expect(screen.getByTestId("saved-parameters")).toBeInTheDocument();
+    // switch back
+    await userEvent.click(screen.getByTestId("parameter-tab"));
+    await waitFor(() => {
+      expect(screen.getByTestId("parameter-tab")).toHaveAttribute(
+        "aria-selected",
+        "true"
+      );
+    });
+    // write some stuff in parameter name
+    const parameterInput = screen.getByTestId(
+      "parameter-name-input"
+    ) as HTMLInputElement;
+    userEvent.type(parameterInput, "SomeText");
+    expect(parameterInput.value).toBe("SomeText");
+    // we now see expression edtior
+    const editor = screen.getByTestId(
+      "terminology-section-sub-header-content-Expression Editor"
+    );
+    expect(editor).toBeVisible();
+
+    //paste into editor, check it's there
+    const editorValue = "Some more Text";
+    let aceEditor: any = await result.container.querySelector(
+      "#ace-editor-wrapper textarea"
+    );
+    userEvent.paste(aceEditor, editorValue);
+    aceEditor = await result.container.querySelector(
+      "#ace-editor-wrapper textarea"
+    );
+    expect(aceEditor.value).toContain(editorValue);
+    // check that clear does anything
+    userEvent.click(getByTestId("apply-parameter-btn"));
+    await waitFor(() => {
+      expect(applyParameter).toHaveBeenCalledWith({
+        expression: "Some more Text",
+        parameterName: "SomeText",
+      });
+      expect(parameterInput.value).toContain("SomeText");
+      expect(aceEditor.value).toContain("Some more Text");
+    });
+  });
 });
diff --git a/src/CqlBuilderPanel/CqlBuilderPanel.tsx b/src/CqlBuilderPanel/CqlBuilderPanel.tsx
index a607881e..c4a08356 100644
--- a/src/CqlBuilderPanel/CqlBuilderPanel.tsx
+++ b/src/CqlBuilderPanel/CqlBuilderPanel.tsx
@@ -27,6 +27,7 @@ export default function CqlBuilderPanel({
   handleDeleteLibrary,
   handleEditLibrary,
   handleApplyCode,
+  handleApplyParameter,
   handleApplyValueSet,
   handleApplyDefinition,
   handleDefinitionEdit,
@@ -219,7 +220,9 @@ export default function CqlBuilderPanel({
             handleApplyCode={handleApplyCode}
           />
         )}
-        {activeTab === "parameters" && <Parameters />}
+        {activeTab === "parameters" && (
+          <Parameters handleApplyParameter={handleApplyParameter} />
+        )}
 
         {activeTab === "definitions" && (
           <DefinitionsSection
diff --git a/src/CqlBuilderPanel/Parameters/ParameterPane.tsx b/src/CqlBuilderPanel/Parameters/ParameterPane.tsx
index 358c5aa0..9cb89dfd 100644
--- a/src/CqlBuilderPanel/Parameters/ParameterPane.tsx
+++ b/src/CqlBuilderPanel/Parameters/ParameterPane.tsx
@@ -12,21 +12,26 @@ const validationSchema = Yup.object({
       "Only alphanumeric characters are allowed, no spaces."
     )
     .required("Parameter Name is required"),
-  expressionEditorValue: Yup.string(),
+  parameterExpression: Yup.string(),
 });
 
-export default function ParameterPane() {
+export default function ParameterPane({ handleApplyParameter }) {
   const textAreaRef = useRef(null);
   const [editorHeight, setEditorHeight] = useState("100px");
   const [showEditor, setShowEditor] = useState(false);
   const formik = useFormik({
     initialValues: {
       parameterName: "",
-      expressionEditorValue: "",
+      expression: "",
     },
     validationSchema,
     enableReinitialize: true,
-    onSubmit: (values) => {},
+    onSubmit: async (values) => {
+      const result = handleApplyParameter(values);
+      if (result === "success") {
+        formik.resetForm();
+      }
+    },
   });
   const { resetForm } = formik;
   // adjusting the height of the editor based on the inserted text
@@ -36,7 +41,7 @@ export default function ParameterPane() {
       const newHeight = Math.max(lineCount * 20, 100) + "px";
       setEditorHeight(newHeight);
     }
-  }, [formik.values.expressionEditorValue]);
+  }, [formik.values.expression]);
   return (
     <>
       <div className="row">
@@ -65,9 +70,9 @@ export default function ParameterPane() {
           mode="sql"
           ref={textAreaRef}
           theme="monokai"
-          value={formik.values.expressionEditorValue}
+          value={formik.values.expression}
           onChange={(value) => {
-            formik.setFieldValue("expressionEditorValue", value);
+            formik.setFieldValue("expression", value);
           }}
           onLoad={(aceEditor) => {
             // On load we want to tell the ace editor that it's inside of a scrollabel page
@@ -93,8 +98,9 @@ export default function ParameterPane() {
           Clear
         </Button>
         <Button
-          data-testId="apply-parameter"
+          data-testId="apply-parameter-btn"
           disabled={!formik.dirty || !formik.isValid}
+          onClick={formik.handleSubmit}
         >
           Apply
         </Button>
diff --git a/src/CqlBuilderPanel/Parameters/Parameters.tsx b/src/CqlBuilderPanel/Parameters/Parameters.tsx
index 56b9c672..58c03e12 100644
--- a/src/CqlBuilderPanel/Parameters/Parameters.tsx
+++ b/src/CqlBuilderPanel/Parameters/Parameters.tsx
@@ -3,14 +3,16 @@ import ParametersNavTabs from "./ParamatersNavTabs";
 import ParameterPane from "./ParameterPane";
 import "./Parameters.scss";
 
-export default function Parameters() {
+export default function Parameters({ handleApplyParameter }) {
   const [activeTab, setActiveTab] = useState("parameters");
 
   return (
     <form id="cql-editor-parameters" data-testId="cql-editor-parameters">
       <ParametersNavTabs activeTab={activeTab} setActiveTab={setActiveTab} />
 
-      {activeTab === "parameters" && <ParameterPane />}
+      {activeTab === "parameters" && (
+        <ParameterPane handleApplyParameter={handleApplyParameter} />
+      )}
       {activeTab === "savedParameters" && (
         <div data-testId="saved-parameters" />
       )}
diff --git a/src/api/useTerminologyServiceApi.ts b/src/api/useTerminologyServiceApi.ts
index d4fcab6a..f542ad56 100644
--- a/src/api/useTerminologyServiceApi.ts
+++ b/src/api/useTerminologyServiceApi.ts
@@ -24,6 +24,11 @@ export type ValueSet = {
   errorMsg: string;
 };
 
+export type Parameter = {
+  parameterName?: string;
+  expression?: string;
+};
+
 export interface CodeSystem {
   id: string;
   lastUpdated: string;
diff --git a/src/cqlEditorWithTerminology/CqlEditorWithTerminology.tsx b/src/cqlEditorWithTerminology/CqlEditorWithTerminology.tsx
index 78d517ee..73d883de 100644
--- a/src/cqlEditorWithTerminology/CqlEditorWithTerminology.tsx
+++ b/src/cqlEditorWithTerminology/CqlEditorWithTerminology.tsx
@@ -14,6 +14,7 @@ const CqlEditorWithTerminology = ({
   handleCodeDelete,
   handleDefinitionDelete,
   handleApplyCode,
+  handleApplyParameter,
   handleApplyValueSet,
   handleApplyDefinition,
   handleApplyLibrary,
@@ -106,6 +107,7 @@ const CqlEditorWithTerminology = ({
               setIsCQLUnchanged={setIsCQLUnchanged}
               isCQLUnchanged={isCQLUnchanged}
               handleApplyCode={handleApplyCode}
+              handleApplyParameter={handleApplyParameter}
               handleApplyValueSet={handleApplyValueSet}
               handleApplyDefinition={handleApplyDefinition}
               handleDefinitionEdit={handleDefinitionEdit}