Index: flang/docs/Intrinsics.md
===================================================================
--- flang/docs/Intrinsics.md
+++ flang/docs/Intrinsics.md
@@ -746,7 +746,7 @@
 
 | Intrinsic Category | Intrinsic Procedures Lacking Support |
 | --- | --- |
-| Coarray intrinsic functions | LCOBOUND, UCOBOUND, FAILED_IMAGES, GET_TEAM, IMAGE_INDEX, STOPPED_IMAGES, TEAM_NUMBER, COSHAPE |
+| Coarray intrinsic functions | LCOBOUND, UCOBOUND, FAILED_IMAGES, GET_TEAM, IMAGE_INDEX, STOPPED_IMAGES, COSHAPE |
 | Object characteristic inquiry functions | ALLOCATED, ASSOCIATED, EXTENDS_TYPE_OF, IS_CONTIGUOUS, PRESENT, RANK, SAME_TYPE, STORAGE_SIZE |
 | Type inquiry intrinsic functions | BIT_SIZE, DIGITS, EPSILON, HUGE, KIND, MAXEXPONENT, MINEXPONENT, NEW_LINE, PRECISION, RADIX, RANGE, TINY|
 | Non-standard intrinsic functions | AND, OR, XOR, LSHIFT, RSHIFT, SHIFT, ZEXT, IZEXT, COSD, SIND, TAND, ACOSD, ASIND, ATAND, ATAN2D, COMPL, DCMPLX, EQV, NEQV, INT8, JINT, JNINT, KNINT, LOC, QCMPLX, DREAL, DFLOAT, QEXT, QFLOAT, QREAL, DNUM, NUM, JNUM, KNUM, QNUM, RNUM, RAN, RANF, ILEN, SIZEOF, MCLOCK, SECNDS, COTAN, IBCHNG, ISHA, ISHC, ISHL, IXOR, IARG, IARGC, NARGS, NUMARG, BADDRESS, IADDR, CACHESIZE, EOF, FP_CLASS, INT_PTR_KIND, ISNAN, MALLOC |
Index: flang/lib/Evaluate/intrinsics.cpp
===================================================================
--- flang/lib/Evaluate/intrinsics.cpp
+++ flang/lib/Evaluate/intrinsics.cpp
@@ -105,7 +105,7 @@
 static constexpr TypePattern DefaultLogical{
     LogicalType, KindCode::defaultLogicalKind};
 static constexpr TypePattern BOZ{IntType, KindCode::typeless};
-static constexpr TypePattern TEAM_TYPE{IntType, KindCode::teamType};
+static constexpr TypePattern TEAM_TYPE{DerivedType, KindCode::teamType};
 static constexpr TypePattern DoublePrecision{
     RealType, KindCode::doublePrecision};
 static constexpr TypePattern DoublePrecisionComplex{
@@ -237,6 +237,8 @@
     common::Intent::In};
 static constexpr IntrinsicDummyArgument OptionalMASK{"mask", AnyLogical,
     Rank::conformable, Optionality::optional, common::Intent::In};
+static constexpr IntrinsicDummyArgument RequiredTEAM{
+    "team", TEAM_TYPE, Rank::scalar, Optionality::required, common::Intent::In};
 
 struct IntrinsicInterface {
   static constexpr int maxArguments{7}; // if not a MAX/MIN(...)
@@ -746,6 +748,10 @@
     {"tan", {{"x", SameFloating}}, SameFloating},
     {"tand", {{"x", SameFloating}}, SameFloating},
     {"tanh", {{"x", SameFloating}}, SameFloating},
+    {"team_number", {}, DefaultInt, Rank::scalar,
+        IntrinsicClass::transformationalFunction},
+    {"team_number", {RequiredTEAM}, DefaultInt, Rank::scalar,
+        IntrinsicClass::transformationalFunction},
     // optional team dummy arguments needed to complete the following
     // this_image versions
     {"this_image", {{"coarray", AnyData, Rank::coarray}, OptionalDIM},
@@ -825,7 +831,7 @@
 
 // TODO: Coarray intrinsic functions
 //   LCOBOUND, UCOBOUND, FAILED_IMAGES, GET_TEAM, IMAGE_INDEX,
-//   STOPPED_IMAGES, TEAM_NUMBER, COSHAPE
+//   STOPPED_IMAGES, COSHAPE
 // TODO: Non-standard intrinsic functions
 //  AND, OR, XOR, LSHIFT, RSHIFT, SHIFT, ZEXT, IZEXT,
 //  COMPL, EQV, NEQV, INT8, JINT, JNINT, KNINT,
@@ -1293,9 +1299,12 @@
     switch (d.typePattern.kindCode) {
     case KindCode::none:
     case KindCode::typeless:
-    case KindCode::teamType: // TODO: TEAM_TYPE
       argOk = false;
       break;
+    case KindCode::teamType:
+      argOk = type->GetDerivedTypeSpec().typeSymbol().name() ==
+          "__builtin_team_type";
+      break;
     case KindCode::defaultIntegerKind:
       argOk = type->kind() == defaults.GetDefaultKind(TypeCategory::Integer);
       break;
@@ -1726,6 +1735,10 @@
       CHECK(d.optionality != Optionality::required);
       if (d.typePattern.kindCode == KindCode::same) {
         dummyArgs.emplace_back(dummyArgs[sameDummyArg.value()]);
+      } else if (d.typePattern.kindCode == KindCode::teamType) {
+        common::die("INTERNAL: missing optional TEAM_TYPE dummy argument is "
+                    "unimplemented");
+        return std::nullopt;
       } else {
         auto category{d.typePattern.categorySet.LeastElement().value()};
         characteristics::TypeAndShape typeAndShape{
Index: flang/test/Semantics/team_number.f90
===================================================================
--- /dev/null
+++ flang/test/Semantics/team_number.f90
@@ -0,0 +1,21 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1
+! Check for semantic errors in team_number() function calls
+
+subroutine test
+  use, intrinsic :: iso_fortran_env, only: team_type
+  type(team_type) :: oregon
+
+  ! correct calls, should produce no errors
+  print *, team_number()
+  print *, team_number(oregon)
+  print *, team_number(team=oregon)
+
+  ! call with too many arguments
+  !ERROR: too many actual arguments for intrinsic 'team_number'
+  print *, team_number(1, 3)
+
+  ! keyword argument with incorrect type
+  !ERROR: unknown keyword argument to intrinsic 'team_number'
+  print *, team_number(team=3.1415)
+
+end subroutine
Index: flang/unittests/Evaluate/intrinsics.cpp
===================================================================
--- flang/unittests/Evaluate/intrinsics.cpp
+++ flang/unittests/Evaluate/intrinsics.cpp
@@ -156,6 +156,8 @@
   using Complex8 = Type<TypeCategory::Complex, 8>;
   using Char = Type<TypeCategory::Character, 1>;
   using Log4 = Type<TypeCategory::Logical, 4>;
+  // For testing team arguments (fails to compile)
+  // using Team = Type<TypeCategory::Derived, 0>;
 
   TestCall{defaults, table, "bad"}
       .Push(Const(Scalar<Int4>{}))
@@ -294,6 +296,35 @@
       .Push(Const(Scalar<Real4>{}))
       .DoCall(); // bad type
 
+  TestCall{defaults, table, "team_number"}.DoCall(Int4::GetType());
+  TestCall{defaults, table, "team_number"}
+      .Push(Const(Scalar<Int4>{}))
+      .Push(Const(Scalar<Int4>{}))
+      .DoCall(); // too many args
+  TestCall{defaults, table, "team_number"}
+      .Push(Named("bad", Const(Scalar<Int4>{})))
+      .DoCall(); // bad keyword
+  TestCall{defaults, table, "team_number"}
+      .Push(Const(Scalar<Int4>{}))
+      .DoCall(); // bad type
+  TestCall{defaults, table, "team_number"}
+      .Push(Const(Scalar<Char>{}))
+      .DoCall(); // bad type
+  TestCall{defaults, table, "team_number"}
+      .Push(Const(Scalar<Log4>{}))
+      .DoCall(); // bad type
+  TestCall{defaults, table, "team_number"}
+      .Push(Const(Scalar<Complex8>{}))
+      .DoCall(); // bad type
+  TestCall{defaults, table, "team_number"}
+      .Push(Const(Scalar<Real4>{}))
+      .DoCall(); // bad type
+
+  // TODO: test TEAM argument
+  //  TestCall{defaults, table, "team_number"}
+  //  .Push(Const(Scalar<Team>{}))
+  //  .DoCall(Int4::GetType());
+
   // TODO: test other intrinsics
 
   // Test unrestricted specific to generic name mapping (table 16.2).