diff --git a/examples/typescript/exec-age.ts b/examples/typescript/exec-age.ts
index cd1ffc4db..ae9cd317b 100644
--- a/examples/typescript/exec-age.ts
+++ b/examples/typescript/exec-age.ts
@@ -1,7 +1,7 @@
 /* eslint-disable no-console */
 /* eslint-disable @typescript-eslint/no-var-requires */
 import cql from '../../src/cql';
-const measure = require('./age.json');
+import * as measure from './age.json'; // Ensure "resolveJsonModule" is set to true in tsconfig.json
 
 const lib = new cql.Library(measure);
 const executor = new cql.Executor(lib);
diff --git a/src/runtime/context.ts b/src/runtime/context.ts
index 789c00345..066292b81 100644
--- a/src/runtime/context.ts
+++ b/src/runtime/context.ts
@@ -1,10 +1,10 @@
 import { Exception } from '../datatypes/exception';
 import { typeIsArray } from '../util/util';
 import * as dt from '../datatypes/datatypes';
-import { CodeService } from '../cql-code-service';
 import { MessageListener, NullMessageListener } from './messageListeners';
 import { Patient } from '../cql-patient';
 import { Parameter } from '../types/runtime-types';
+import { TerminologyProvider } from '../types';
 
 export class Context {
   // Public Construcor args
@@ -13,7 +13,7 @@ export class Context {
   public messageListener?: MessageListener;
 
   // Private Construcor args
-  private _codeService?: CodeService | null;
+  private _codeService?: TerminologyProvider | null;
   private _parameters?: Parameter;
 
   // Auto-initialized properties
@@ -24,7 +24,7 @@ export class Context {
 
   constructor(
     parent: Context,
-    _codeService?: CodeService | null,
+    _codeService?: TerminologyProvider | null,
     _parameters?: Parameter,
     executionDateTime?: dt.DateTime,
     messageListener?: MessageListener
@@ -51,7 +51,7 @@ export class Context {
     this._parameters = params;
   }
 
-  get codeService(): CodeService {
+  get codeService(): TerminologyProvider {
     return this._codeService || (this.parent && this.parent.codeService);
   }
 
@@ -64,7 +64,7 @@ export class Context {
     return this;
   }
 
-  withCodeService(cs: CodeService) {
+  withCodeService(cs: TerminologyProvider) {
     this.codeService = cs;
     return this;
   }
@@ -423,7 +423,7 @@ export class PatientContext extends Context {
   constructor(
     public library: any,
     public patient?: Patient | null,
-    codeService?: CodeService | null,
+    codeService?: TerminologyProvider | null,
     parameters?: Parameter,
     executionDateTime: dt.DateTime = dt.DateTime.fromJSDate(new Date()),
     messageListener: MessageListener = new NullMessageListener()
@@ -472,7 +472,7 @@ export class UnfilteredContext extends Context {
   constructor(
     public library: any,
     public results: any,
-    codeService?: CodeService | null,
+    codeService?: TerminologyProvider | null,
     parameters?: Parameter,
     executionDateTime: dt.DateTime = dt.DateTime.fromJSDate(new Date()),
     messageListener: MessageListener = new NullMessageListener()
diff --git a/src/runtime/executor.ts b/src/runtime/executor.ts
index 01be8729d..90016e595 100644
--- a/src/runtime/executor.ts
+++ b/src/runtime/executor.ts
@@ -1,14 +1,14 @@
 import { MessageListener, NullMessageListener } from './messageListeners';
 import { Results } from './results';
 import { UnfilteredContext, PatientContext } from './context';
-import { CodeService } from '../cql-code-service';
 import { DateTime } from '../datatypes/datetime';
 import { Parameter } from '../types/runtime-types';
+import { DataProvider, TerminologyProvider } from '../types';
 
 export class Executor {
   constructor(
     public library: any,
-    public codeService?: CodeService,
+    public codeService?: TerminologyProvider,
     public parameters?: Parameter,
     public messageListener: MessageListener = new NullMessageListener()
   ) {
@@ -28,7 +28,7 @@ export class Executor {
     return this;
   }
 
-  withCodeService(cs: CodeService) {
+  withCodeService(cs: TerminologyProvider) {
     this.codeService = cs;
     return this;
   }
@@ -38,7 +38,7 @@ export class Executor {
     return this;
   }
 
-  exec_expression(expression: any, patientSource: any, executionDateTime: DateTime) {
+  exec_expression(expression: any, patientSource: DataProvider, executionDateTime: DateTime) {
     const r = new Results();
     const expr = this.library.expressions[expression];
     if (expr != null) {
@@ -58,7 +58,7 @@ export class Executor {
     return r;
   }
 
-  exec(patientSource: any, executionDateTime?: DateTime) {
+  exec(patientSource: DataProvider, executionDateTime?: DateTime) {
     const r = this.exec_patient_context(patientSource, executionDateTime);
     const unfilteredContext = new UnfilteredContext(
       this.library,
@@ -79,7 +79,7 @@ export class Executor {
     return r;
   }
 
-  exec_patient_context(patientSource: any, executionDateTime?: DateTime) {
+  exec_patient_context(patientSource: DataProvider, executionDateTime?: DateTime) {
     const r = new Results();
     while (patientSource.currentPatient()) {
       const patient_ctx = new PatientContext(
diff --git a/src/types/cql-code-service-types.ts b/src/types/cql-code-service.interfaces.ts
similarity index 100%
rename from src/types/cql-code-service-types.ts
rename to src/types/cql-code-service.interfaces.ts
diff --git a/src/types/cql-patient-types.ts b/src/types/cql-patient.interfaces.ts
similarity index 100%
rename from src/types/cql-patient-types.ts
rename to src/types/cql-patient.interfaces.ts
diff --git a/src/types/index.ts b/src/types/index.ts
index 4aa723025..39d627ec5 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -1,3 +1,3 @@
 export * from './runtime-types';
-export * from './cql-code-service-types';
-export * from './cql-patient-types';
+export * from './cql-code-service.interfaces';
+export * from './cql-patient.interfaces';