diff --git a/javascript/ql/lib/semmle/javascript/JSDoc.qll b/javascript/ql/lib/semmle/javascript/JSDoc.qll
index 0f95023ce1f..85b7695cd70 100644
--- a/javascript/ql/lib/semmle/javascript/JSDoc.qll
+++ b/javascript/ql/lib/semmle/javascript/JSDoc.qll
@@ -415,7 +415,7 @@ class JSDocNamedTypeExpr extends JSDocTypeExpr {
    * - `foo.bar.Baz` has prefix `foo` and suffix `.bar.Baz`.
    * - `Baz` has prefix `Baz` and an empty suffix.
    */
-  predicate hasNameParts(string prefix, string suffix) {
+  deprecated predicate hasNameParts(string prefix, string suffix) {
     not this = any(JSDocQualifiedTypeAccess a).getBase() and // restrict size of predicate
     exists(string regex, string name | regex = "([^.]+)(.*)" |
       name = this.getRawName() and
@@ -423,46 +423,6 @@ class JSDocNamedTypeExpr extends JSDocTypeExpr {
       suffix = name.regexpCapture(regex, 2)
     )
   }
-
-  pragma[noinline]
-  pragma[nomagic]
-  private predicate hasNamePartsAndEnv(string prefix, string suffix, JSDoc::Environment env) {
-    // Force join ordering
-    this.hasNameParts(prefix, suffix) and
-    env.isContainerInScope(this.getContainer())
-  }
-
-  /**
-   * Gets the qualified name of this name by resolving its prefix, if any.
-   */
-  cached
-  private string resolvedName() {
-    exists(string prefix, string suffix, JSDoc::Environment env |
-      this.hasNamePartsAndEnv(prefix, suffix, env) and
-      result = env.resolveAlias(prefix) + suffix
-    )
-  }
-
-  override predicate hasQualifiedName(string globalName) {
-    globalName = this.resolvedName()
-    or
-    not exists(this.resolvedName()) and
-    globalName = this.getRawName()
-  }
-
-  override DataFlow::ClassNode getClass() {
-    exists(string name |
-      this.hasQualifiedName(name) and
-      result.hasQualifiedName(name)
-    )
-    or
-    // Handle case where a local variable has a reference to the class,
-    // but the class doesn't have a globally qualified name.
-    exists(string alias, JSDoc::Environment env |
-      this.hasNamePartsAndEnv(alias, "", env) and
-      result.getAClassReference().flowsTo(env.getNodeFromAlias(alias))
-    )
-  }
 }
 
 /**
@@ -491,12 +451,6 @@ class JSDocAppliedTypeExpr extends @jsdoc_applied_type_expr, JSDocTypeExpr {
    * For example, in `Array<string>`, `string` is the only argument type.
    */
   JSDocTypeExpr getAnArgument() { result = this.getArgument(_) }
-
-  override predicate hasQualifiedName(string globalName) {
-    this.getHead().hasQualifiedName(globalName)
-  }
-
-  override DataFlow::ClassNode getClass() { result = this.getHead().getClass() }
 }
 
 /**
@@ -516,8 +470,6 @@ class JSDocNullableTypeExpr extends @jsdoc_nullable_type_expr, JSDocTypeExpr {
   predicate isPrefix() { jsdoc_prefix_qualifier(this) }
 
   override JSDocTypeExpr getAnUnderlyingType() { result = this.getTypeExpr().getAnUnderlyingType() }
-
-  override DataFlow::ClassNode getClass() { result = this.getTypeExpr().getClass() }
 }
 
 /**
@@ -537,8 +489,6 @@ class JSDocNonNullableTypeExpr extends @jsdoc_non_nullable_type_expr, JSDocTypeE
   predicate isPrefix() { jsdoc_prefix_qualifier(this) }
 
   override JSDocTypeExpr getAnUnderlyingType() { result = this.getTypeExpr().getAnUnderlyingType() }
-
-  override DataFlow::ClassNode getClass() { result = this.getTypeExpr().getClass() }
 }
 
 /**
@@ -643,8 +593,6 @@ class JSDocOptionalParameterTypeExpr extends @jsdoc_optional_type_expr, JSDocTyp
   override JSDocTypeExpr getAnUnderlyingType() {
     result = this.getUnderlyingType().getAnUnderlyingType()
   }
-
-  override DataFlow::ClassNode getClass() { result = this.getUnderlyingType().getClass() }
 }
 
 /**
@@ -679,7 +627,7 @@ module JSDoc {
   /**
    * A statement container which may declare JSDoc name aliases.
    */
-  class Environment extends StmtContainer {
+  deprecated class Environment extends StmtContainer {
     /**
      * Gets the fully qualified name aliased by the given unqualified name
      * within this container.
@@ -729,7 +677,7 @@ module JSDoc {
   }
 
   pragma[noinline]
-  private predicate isTypenamePrefix(string name) {
+  deprecated private predicate isTypenamePrefix(string name) {
     any(JSDocNamedTypeExpr expr).hasNameParts(name, _)
   }
 }
diff --git a/javascript/ql/lib/semmle/javascript/TypeAnnotations.qll b/javascript/ql/lib/semmle/javascript/TypeAnnotations.qll
index d10b60b92b5..318ad2f8873 100644
--- a/javascript/ql/lib/semmle/javascript/TypeAnnotations.qll
+++ b/javascript/ql/lib/semmle/javascript/TypeAnnotations.qll
@@ -4,6 +4,8 @@
 
 import javascript
 private import internal.StmtContainers
+private import internal.NameResolution
+private import internal.UnderlyingTypes
 
 /**
  * A type annotation, either in the form of a TypeScript type or a JSDoc comment.
@@ -75,14 +77,38 @@ class TypeAnnotation extends @type_annotation, NodeInStmtContainer {
   TypeAnnotation getAnUnderlyingType() { result = this }
 
   /**
+   * DEPRECATED. Use `hasUnderlyingType` instead.
+   *
    * Holds if this is a reference to the type with qualified name `globalName` relative to the global scope.
    */
-  predicate hasQualifiedName(string globalName) { none() }
+  deprecated predicate hasQualifiedName(string globalName) {
+    UnderlyingTypes::nodeHasUnderlyingType(this, globalName)
+  }
 
   /**
+   * DEPRECATED. Use `hasUnderlyingType` instead.
+   *
    * Holds if this is a reference to the type exported from `moduleName` under the name `exportedName`.
    */
-  predicate hasQualifiedName(string moduleName, string exportedName) { none() }
+  deprecated predicate hasQualifiedName(string moduleName, string exportedName) {
+    UnderlyingTypes::nodeHasUnderlyingType(this, moduleName, exportedName)
+  }
+
+  /**
+   * Holds if this is a reference to the type with qualified name `globalName` relative to the global scope,
+   * or is declared as a subtype thereof, or is a union or intersection containing such a type.
+   */
+  final predicate hasUnderlyingType(string globalName) {
+    UnderlyingTypes::nodeHasUnderlyingType(this, globalName)
+  }
+
+  /**
+   * Holds if this is a reference to the type exported from `moduleName` under the name `exportedName`,
+   * or is declared as a subtype thereof, or is a union or intersection containing such a type.
+   */
+  final predicate hasUnderlyingType(string moduleName, string exportedName) {
+    UnderlyingTypes::nodeHasUnderlyingType(this, moduleName, exportedName)
+  }
 
   /** Gets the statement in which this type appears. */
   Stmt getEnclosingStmt() { none() }
@@ -107,5 +133,5 @@ class TypeAnnotation extends @type_annotation, NodeInStmtContainer {
    *
    * This unfolds nullability modifiers and generic type applications.
    */
-  DataFlow::ClassNode getClass() { none() }
+  final DataFlow::ClassNode getClass() { UnderlyingTypes::nodeHasUnderlyingClassType(this, result) }
 }
diff --git a/javascript/ql/lib/semmle/javascript/TypeScript.qll b/javascript/ql/lib/semmle/javascript/TypeScript.qll
index d8b6b63a366..f11ff776309 100644
--- a/javascript/ql/lib/semmle/javascript/TypeScript.qll
+++ b/javascript/ql/lib/semmle/javascript/TypeScript.qll
@@ -1,4 +1,5 @@
 import javascript
+private import semmle.javascript.internal.UnderlyingTypes
 
 /**
  * A statement that defines a namespace, that is, a namespace declaration or enum declaration.
@@ -575,10 +576,6 @@ class TypeExpr extends ExprOrType, @typeexpr, TypeAnnotation {
   override Function getEnclosingFunction() { result = ExprOrType.super.getEnclosingFunction() }
 
   override TopLevel getTopLevel() { result = ExprOrType.super.getTopLevel() }
-
-  override DataFlow::ClassNode getClass() {
-    result.getAstNode() = this.getType().(ClassType).getClass()
-  }
 }
 
 /**
@@ -698,58 +695,9 @@ class TypeAccess extends @typeaccess, TypeExpr, TypeRef {
    */
   TypeName getTypeName() { ast_node_symbol(this, result) }
 
-  override predicate hasQualifiedName(string globalName) {
-    this.getTypeName().hasQualifiedName(globalName)
-    or
-    exists(LocalTypeAccess local | local = this |
-      not exists(local.getLocalTypeName()) and // Without a local type name, the type is looked up in the global scope.
-      globalName = local.getName()
-    )
-  }
-
-  override predicate hasQualifiedName(string moduleName, string exportedName) {
-    this.getTypeName().hasQualifiedName(moduleName, exportedName)
-    or
-    exists(ImportDeclaration imprt, ImportSpecifier spec |
-      moduleName = getImportName(imprt) and
-      spec = imprt.getASpecifier()
-    |
-      spec.getImportedName() = exportedName and
-      this = spec.getLocal().(TypeDecl).getLocalTypeName().getAnAccess()
-      or
-      (spec instanceof ImportNamespaceSpecifier or spec instanceof ImportDefaultSpecifier) and
-      this =
-        spec.getLocal().(LocalNamespaceDecl).getLocalNamespaceName().getAMemberAccess(exportedName)
-    )
-    or
-    exists(ImportEqualsDeclaration imprt |
-      moduleName = getImportName(imprt.getImportedEntity()) and
-      this =
-        imprt
-            .getIdentifier()
-            .(LocalNamespaceDecl)
-            .getLocalNamespaceName()
-            .getAMemberAccess(exportedName)
-    )
-  }
-
   override string getAPrimaryQlClass() { result = "TypeAccess" }
 }
 
-/**
- * Gets a suitable name for the library imported by `imprt`.
- *
- * For relative imports, this is the snapshot-relative path to the imported module.
- * For non-relative imports, it is the import path itself.
- */
-private string getImportName(Import imprt) {
-  exists(string path | path = imprt.getImportedPath().getValue() |
-    if path.regexpMatch("[./].*")
-    then result = imprt.getImportedModule().getFile().getRelativePath()
-    else result = path
-  )
-}
-
 /** An identifier that is used as part of a type, such as `Date`. */
 class LocalTypeAccess extends @local_type_access, TypeAccess, Identifier, LexicalAccess {
   override predicate isStringy() { this.getName() = "String" }
@@ -822,14 +770,6 @@ class GenericTypeExpr extends @generic_typeexpr, TypeExpr {
   /** Gets the number of type arguments. This is always at least one. */
   int getNumTypeArgument() { result = count(this.getATypeArgument()) }
 
-  override predicate hasQualifiedName(string globalName) {
-    this.getTypeAccess().hasQualifiedName(globalName)
-  }
-
-  override predicate hasQualifiedName(string moduleName, string exportedName) {
-    this.getTypeAccess().hasQualifiedName(moduleName, exportedName)
-  }
-
   override string getAPrimaryQlClass() { result = "GenericTypeExpr" }
 }
 
diff --git a/javascript/ql/lib/semmle/javascript/frameworks/Nest.qll b/javascript/ql/lib/semmle/javascript/frameworks/Nest.qll
index dd6e1a7d915..89b7fe04997 100644
--- a/javascript/ql/lib/semmle/javascript/frameworks/Nest.qll
+++ b/javascript/ql/lib/semmle/javascript/frameworks/Nest.qll
@@ -237,7 +237,7 @@ module NestJS {
     CustomPipeClass() {
       exists(ClassDefinition cls |
         this = cls.flow() and
-        cls.getASuperInterface().hasQualifiedName("@nestjs/common", "PipeTransform")
+        cls.getASuperInterface().hasUnderlyingType("@nestjs/common", "PipeTransform")
       )
     }
 
diff --git a/javascript/ql/test/library-tests/JSDoc/NameResolution/test.expected b/javascript/ql/test/library-tests/JSDoc/NameResolution/test.expected
index 97730513195..7c015994aaf 100644
--- a/javascript/ql/test/library-tests/JSDoc/NameResolution/test.expected
+++ b/javascript/ql/test/library-tests/JSDoc/NameResolution/test.expected
@@ -1,10 +1,10 @@
-| bar.js:5:14:5:14 | x | x |
+| bar.js:5:14:5:14 | x | ns.very.long.namespace |
 | bar.js:5:14:5:18 | x.Foo | ns.very.long.namespace.Foo |
-| bar.js:12:14:12:17 | iife | iife |
+| bar.js:12:14:12:17 | iife | IIFE |
 | bar.js:12:14:12:21 | iife.Foo | IIFE.Foo |
 | closure.js:8:12:8:15 | goog | goog |
 | closure.js:8:12:8:19 | goog.net | goog.net |
 | closure.js:8:12:8:28 | goog.net.SomeType | goog.net.SomeType |
-| closure.js:9:12:9:14 | net | net |
+| closure.js:9:12:9:14 | net | goog.net |
 | closure.js:9:12:9:23 | net.SomeType | goog.net.SomeType |
 | closure.js:10:12:10:19 | SomeType | goog.net.SomeType |
diff --git a/javascript/ql/test/library-tests/JSDoc/NameResolution/test.ql b/javascript/ql/test/library-tests/JSDoc/NameResolution/test.ql
index 1b7ebfdd501..bb1de953169 100644
--- a/javascript/ql/test/library-tests/JSDoc/NameResolution/test.ql
+++ b/javascript/ql/test/library-tests/JSDoc/NameResolution/test.ql
@@ -1,3 +1,3 @@
 import javascript
 
-query string test_hasQualifiedName(JSDocNamedTypeExpr expr) { expr.hasQualifiedName(result) }
+query string test_hasUnderlyingType(JSDocNamedTypeExpr expr) { expr.hasUnderlyingType(result) }
diff --git a/javascript/ql/test/library-tests/TypeAnnotations/JSDoc/JSDocTypeAnnotations.expected b/javascript/ql/test/library-tests/TypeAnnotations/JSDoc/JSDocTypeAnnotations.expected
index 8ac3eea2be5..06afe15ee18 100644
--- a/javascript/ql/test/library-tests/TypeAnnotations/JSDoc/JSDocTypeAnnotations.expected
+++ b/javascript/ql/test/library-tests/TypeAnnotations/JSDoc/JSDocTypeAnnotations.expected
@@ -2,13 +2,14 @@ test_isString
 | tst.js:2:12:2:17 | string |
 test_isNumber
 | tst.js:3:12:3:17 | number |
-test_QualifiedName
+test_hasUnderlyingType
 | VarType | tst.js:9:13:9:19 | VarType |
 | boolean | tst.js:5:14:5:20 | boolean |
 | foo | tst.js:4:12:4:14 | foo |
 | foo.bar | tst.js:4:12:4:18 | foo.bar |
 | foo.bar.baz | tst.js:4:12:4:22 | foo.bar.baz |
 | number | tst.js:3:12:3:17 | number |
+| number | tst.js:3:12:3:18 | number? |
 | string | tst.js:2:12:2:17 | string |
 test_ParameterType
 | tst.js:7:12:7:12 | x | tst.js:2:12:2:17 | string |
diff --git a/javascript/ql/test/library-tests/TypeAnnotations/JSDoc/JSDocTypeAnnotations.ql b/javascript/ql/test/library-tests/TypeAnnotations/JSDoc/JSDocTypeAnnotations.ql
index 829435e3220..fd223ee5a53 100644
--- a/javascript/ql/test/library-tests/TypeAnnotations/JSDoc/JSDocTypeAnnotations.ql
+++ b/javascript/ql/test/library-tests/TypeAnnotations/JSDoc/JSDocTypeAnnotations.ql
@@ -4,7 +4,7 @@ query TypeAnnotation test_isString() { result.isString() }
 
 query TypeAnnotation test_isNumber() { result.isNumber() }
 
-query TypeAnnotation test_QualifiedName(string name) { result.hasQualifiedName(name) }
+query TypeAnnotation test_hasUnderlyingType(string name) { result.hasUnderlyingType(name) }
 
 query TypeAnnotation test_ParameterType(Parameter p) { result = p.getTypeAnnotation() }
 
diff --git a/javascript/ql/test/library-tests/TypeAnnotations/TSUnresolvedQualifiedName/QualifiedNames.ql b/javascript/ql/test/library-tests/TypeAnnotations/TSUnresolvedQualifiedName/QualifiedNames.ql
index e9d66a4afe0..b4d324377be 100644
--- a/javascript/ql/test/library-tests/TypeAnnotations/TSUnresolvedQualifiedName/QualifiedNames.ql
+++ b/javascript/ql/test/library-tests/TypeAnnotations/TSUnresolvedQualifiedName/QualifiedNames.ql
@@ -1,5 +1,5 @@
 import javascript
 
 from TypeAnnotation type, string mod, string name
-where type.hasQualifiedName(mod, name)
+where type.hasUnderlyingType(mod, name)
 select type, mod, name
diff --git a/javascript/ql/test/library-tests/TypeScript/HasQualifiedNameFallback/Test.expected b/javascript/ql/test/library-tests/TypeScript/HasQualifiedNameFallback/Test.expected
index 5ee97e2dfb5..3781aea96e2 100644
--- a/javascript/ql/test/library-tests/TypeScript/HasQualifiedNameFallback/Test.expected
+++ b/javascript/ql/test/library-tests/TypeScript/HasQualifiedNameFallback/Test.expected
@@ -1,13 +1,15 @@
-hasQualifiedNameModule
-| default-import | default | tst.ts:11:9:11:21 | DefaultImport |
+hasUnderlyingTypeModule
+| default-import |  | tst.ts:11:9:11:21 | DefaultImport |
+| global | UnresolvedName | tst.ts:12:9:12:22 | UnresolvedName |
+| import-assign |  | tst.ts:10:9:10:11 | asn |
 | import-assign | Foo | tst.ts:10:9:10:15 | asn.Foo |
 | named-import | Name1 | tst.ts:7:9:7:13 | Name1 |
 | named-import | Name1 | tst.ts:13:9:13:13 | Name1 |
 | named-import | Name1 | tst.ts:13:9:13:21 | Name1<number> |
 | named-import | Name2 | tst.ts:8:9:8:13 | Name2 |
+| namespace-import |  | tst.ts:9:9:9:17 | namespace |
 | namespace-import | Foo | tst.ts:9:9:9:21 | namespace.Foo |
-| tst.ts | ExportedClass | relative.ts:4:8:4:20 | ExportedClass |
-hasQualifiedNameGlobal
+hasUnderlyingTypeGlobal
 | UnresolvedName | tst.ts:12:9:12:22 | UnresolvedName |
 paramExample
 | tst.ts:7:5:7:6 | x1 |
diff --git a/javascript/ql/test/library-tests/TypeScript/HasQualifiedNameFallback/Test.ql b/javascript/ql/test/library-tests/TypeScript/HasQualifiedNameFallback/Test.ql
index 2b63e171f1e..199749ed3f6 100644
--- a/javascript/ql/test/library-tests/TypeScript/HasQualifiedNameFallback/Test.ql
+++ b/javascript/ql/test/library-tests/TypeScript/HasQualifiedNameFallback/Test.ql
@@ -1,13 +1,13 @@
 import javascript
 
-query TypeAnnotation hasQualifiedNameModule(string moduleName, string member) {
-  result.hasQualifiedName(moduleName, member)
+query TypeAnnotation hasUnderlyingTypeModule(string moduleName, string member) {
+  result.hasUnderlyingType(moduleName, member)
 }
 
-query TypeAnnotation hasQualifiedNameGlobal(string globalName) {
-  result.hasQualifiedName(globalName)
+query TypeAnnotation hasUnderlyingTypeGlobal(string globalName) {
+  result.hasUnderlyingType(globalName)
 }
 
 query Parameter paramExample() {
-  result.getTypeAnnotation().hasQualifiedName("named-import", "Name1")
+  result.getTypeAnnotation().hasUnderlyingType("named-import", "Name1")
 }
diff --git a/javascript/ql/test/library-tests/TypeScript/HasUnderlyingType/HasUnderlyingType.expected b/javascript/ql/test/library-tests/TypeScript/HasUnderlyingType/HasUnderlyingType.expected
index a9123b1ef55..e330bb897b7 100644
--- a/javascript/ql/test/library-tests/TypeScript/HasUnderlyingType/HasUnderlyingType.expected
+++ b/javascript/ql/test/library-tests/TypeScript/HasUnderlyingType/HasUnderlyingType.expected
@@ -6,5 +6,4 @@
 underlyingTypeNode
 | foo |  | file://:0:0:0:0 | use moduleImport("foo").getMember("exports") |
 | foo |  | foo.ts:1:8:1:10 | use moduleImport("foo").getMember("exports").getMember("default") |
-| foo | Bar | foo.ts:3:1:5:1 | use moduleImport("foo").getMember("exports").getMember("Bar").getInstance() |
 | foo | Bar | foo.ts:3:12:3:12 | use moduleImport("foo").getMember("exports").getMember("Bar").getInstance() |