diff --git a/Objects/interpreteridobject.c b/Objects/interpreteridobject.c
new file mode 100644
index 0000000..dd142b0
--- /dev/null
+++ b/Objects/interpreteridobject.c
@@ -0,0 +1,308 @@
+/* InterpreterID object */
+
+#include "Python.h"
+#include "internal/pycore_pystate.h"
+#include "interpreteridobject.h"
+
+
+int64_t
+_Py_CoerceID(PyObject *orig)
+{
+    PyObject *pyid = PyNumber_Long(orig);
+    if (pyid == NULL) {
+        if (PyErr_ExceptionMatches(PyExc_TypeError)) {
+            PyErr_Format(PyExc_TypeError,
+                         "'id' must be a non-negative int, got %R", orig);
+        }
+        else {
+            PyErr_Format(PyExc_ValueError,
+                         "'id' must be a non-negative int, got %R", orig);
+        }
+        return -1;
+    }
+    int64_t id = PyLong_AsLongLong(pyid);
+    Py_DECREF(pyid);
+    if (id == -1 && PyErr_Occurred() != NULL) {
+        if (!PyErr_ExceptionMatches(PyExc_OverflowError)) {
+            PyErr_Format(PyExc_ValueError,
+                         "'id' must be a non-negative int, got %R", orig);
+        }
+        return -1;
+    }
+    if (id < 0) {
+        PyErr_Format(PyExc_ValueError,
+                     "'id' must be a non-negative int, got %R", orig);
+        return -1;
+    }
+    return id;
+}
+
+typedef struct interpid {
+    PyObject_HEAD
+    int64_t id;
+} interpid;
+
+static interpid *
+newinterpid(PyTypeObject *cls, int64_t id, int force)
+{
+    PyInterpreterState *interp = _PyInterpreterState_LookUpID(id);
+    if (interp == NULL) {
+        if (force) {
+            PyErr_Clear();
+        }
+        else {
+            return NULL;
+        }
+    }
+
+    interpid *self = PyObject_New(interpid, cls);
+    if (self == NULL) {
+        return NULL;
+    }
+    self->id = id;
+
+    if (interp != NULL) {
+        _PyInterpreterState_IDIncref(interp);
+    }
+    return self;
+}
+
+static PyObject *
+interpid_new(PyTypeObject *cls, PyObject *args, PyObject *kwds)
+{
+    static char *kwlist[] = {"id", "force", NULL};
+    PyObject *idobj;
+    int force = 0;
+    if (!PyArg_ParseTupleAndKeywords(args, kwds,
+                                     "O|$p:InterpreterID.__init__", kwlist,
+                                     &idobj, &force)) {
+        return NULL;
+    }
+
+    // Coerce and check the ID.
+    int64_t id;
+    if (PyObject_TypeCheck(idobj, &_PyInterpreterID_Type)) {
+        id = ((interpid *)idobj)->id;
+    }
+    else {
+        id = _Py_CoerceID(idobj);
+        if (id < 0) {
+            return NULL;
+        }
+    }
+
+    return (PyObject *)newinterpid(cls, id, force);
+}
+
+static void
+interpid_dealloc(PyObject *v)
+{
+    int64_t id = ((interpid *)v)->id;
+    PyInterpreterState *interp = _PyInterpreterState_LookUpID(id);
+    if (interp != NULL) {
+        _PyInterpreterState_IDDecref(interp);
+    }
+    else {
+        // already deleted
+        PyErr_Clear();
+    }
+    Py_TYPE(v)->tp_free(v);
+}
+
+static PyObject *
+interpid_repr(PyObject *self)
+{
+    PyTypeObject *type = Py_TYPE(self);
+    const char *name = _PyType_Name(type);
+    interpid *id = (interpid *)self;
+    return PyUnicode_FromFormat("%s(%" PRId64 ")", name, id->id);
+}
+
+static PyObject *
+interpid_str(PyObject *self)
+{
+    interpid *id = (interpid *)self;
+    return PyUnicode_FromFormat("%" PRId64 "", id->id);
+}
+
+static PyObject *
+interpid_int(PyObject *self)
+{
+    interpid *id = (interpid *)self;
+    return PyLong_FromLongLong(id->id);
+}
+
+static PyNumberMethods interpid_as_number = {
+     0,                       /* nb_add */
+     0,                       /* nb_subtract */
+     0,                       /* nb_multiply */
+     0,                       /* nb_remainder */
+     0,                       /* nb_divmod */
+     0,                       /* nb_power */
+     0,                       /* nb_negative */
+     0,                       /* nb_positive */
+     0,                       /* nb_absolute */
+     0,                       /* nb_bool */
+     0,                       /* nb_invert */
+     0,                       /* nb_lshift */
+     0,                       /* nb_rshift */
+     0,                       /* nb_and */
+     0,                       /* nb_xor */
+     0,                       /* nb_or */
+     (unaryfunc)interpid_int, /* nb_int */
+     0,                       /* nb_reserved */
+     0,                       /* nb_float */
+
+     0,                       /* nb_inplace_add */
+     0,                       /* nb_inplace_subtract */
+     0,                       /* nb_inplace_multiply */
+     0,                       /* nb_inplace_remainder */
+     0,                       /* nb_inplace_power */
+     0,                       /* nb_inplace_lshift */
+     0,                       /* nb_inplace_rshift */
+     0,                       /* nb_inplace_and */
+     0,                       /* nb_inplace_xor */
+     0,                       /* nb_inplace_or */
+
+     0,                       /* nb_floor_divide */
+     0,                       /* nb_true_divide */
+     0,                       /* nb_inplace_floor_divide */
+     0,                       /* nb_inplace_true_divide */
+
+     (unaryfunc)interpid_int, /* nb_index */
+};
+
+static Py_hash_t
+interpid_hash(PyObject *self)
+{
+    interpid *id = (interpid *)self;
+    PyObject *obj = PyLong_FromLongLong(id->id);
+    if (obj == NULL) {
+        return -1;
+    }
+    Py_hash_t hash = PyObject_Hash(obj);
+    Py_DECREF(obj);
+    return hash;
+}
+
+static PyObject *
+interpid_richcompare(PyObject *self, PyObject *other, int op)
+{
+    if (op != Py_EQ && op != Py_NE) {
+        Py_RETURN_NOTIMPLEMENTED;
+    }
+
+    if (!PyObject_TypeCheck(self, &_PyInterpreterID_Type)) {
+        Py_RETURN_NOTIMPLEMENTED;
+    }
+
+    interpid *id = (interpid *)self;
+    int equal;
+    if (PyObject_TypeCheck(other, &_PyInterpreterID_Type)) {
+        interpid *otherid = (interpid *)other;
+        equal = (id->id == otherid->id);
+    }
+    else {
+        other = PyNumber_Long(other);
+        if (other == NULL) {
+            PyErr_Clear();
+            Py_RETURN_NOTIMPLEMENTED;
+        }
+        int64_t otherid = PyLong_AsLongLong(other);
+        Py_DECREF(other);
+        if (otherid == -1 && PyErr_Occurred() != NULL) {
+            return NULL;
+        }
+        if (otherid < 0) {
+            equal = 0;
+        }
+        else {
+            equal = (id->id == otherid);
+        }
+    }
+
+    if ((op == Py_EQ && equal) || (op == Py_NE && !equal)) {
+        Py_RETURN_TRUE;
+    }
+    Py_RETURN_FALSE;
+}
+
+PyDoc_STRVAR(interpid_doc,
+"A interpreter ID identifies a interpreter and may be used as an int.");
+
+PyTypeObject _PyInterpreterID_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    "InterpreterID",   /* tp_name */
+    sizeof(interpid),               /* tp_basicsize */
+    0,                              /* tp_itemsize */
+    (destructor)interpid_dealloc,   /* tp_dealloc */
+    0,                              /* tp_print */
+    0,                              /* tp_getattr */
+    0,                              /* tp_setattr */
+    0,                              /* tp_as_async */
+    (reprfunc)interpid_repr,        /* tp_repr */
+    &interpid_as_number,            /* tp_as_number */
+    0,                              /* tp_as_sequence */
+    0,                              /* tp_as_mapping */
+    interpid_hash,                  /* tp_hash */
+    0,                              /* tp_call */
+    (reprfunc)interpid_str,         /* tp_str */
+    0,                              /* tp_getattro */
+    0,                              /* tp_setattro */
+    0,                              /* tp_as_buffer */
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE |
+        Py_TPFLAGS_LONG_SUBCLASS,   /* tp_flags */
+    interpid_doc,                   /* tp_doc */
+    0,                              /* tp_traverse */
+    0,                              /* tp_clear */
+    interpid_richcompare,           /* tp_richcompare */
+    0,                              /* tp_weaklistoffset */
+    0,                              /* tp_iter */
+    0,                              /* tp_iternext */
+    0,                              /* tp_methods */
+    0,                              /* tp_members */
+    0,                              /* tp_getset */
+    &PyLong_Type,                   /* tp_base */
+    0,                              /* tp_dict */
+    0,                              /* tp_descr_get */
+    0,                              /* tp_descr_set */
+    0,                              /* tp_dictoffset */
+    0,                              /* tp_init */
+    0,                              /* tp_alloc */
+    interpid_new,                   /* tp_new */
+};
+
+PyObject *_PyInterpreterID_New(int64_t id)
+{
+    return (PyObject *)newinterpid(&_PyInterpreterID_Type, id, 0);
+}
+
+PyObject *
+_PyInterpreterState_GetIDObject(PyInterpreterState *interp)
+{
+    if (_PyInterpreterState_IDInitref(interp) != 0) {
+        return NULL;
+    };
+    PY_INT64_T id = PyInterpreterState_GetID(interp);
+    if (id < 0) {
+        return NULL;
+    }
+    return (PyObject *)newinterpid(&_PyInterpreterID_Type, id, 0);
+}
+
+PyInterpreterState *
+_PyInterpreterID_LookUp(PyObject *requested_id)
+{
+    int64_t id;
+    if (PyObject_TypeCheck(requested_id, &_PyInterpreterID_Type)) {
+        id = ((interpid *)requested_id)->id;
+    }
+    else {
+        id = PyLong_AsLongLong(requested_id);
+        if (id == -1 && PyErr_Occurred() != NULL) {
+            return NULL;
+        }
+        assert(id <= INT64_MAX);
+    }
+    return _PyInterpreterState_LookUpID(id);
+}
diff --git a/Objects/object.c b/Objects/object.c
index cf5264b..b446d59 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -5,6 +5,7 @@
 #include "pycore_pystate.h"
 #include "pycore_context.h"
 #include "frameobject.h"
+#include "interpreteridobject.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -1806,6 +1807,7 @@
     INIT_TYPE(&PySeqIter_Type, "sequence iterator");
     INIT_TYPE(&PyCoro_Type, "coroutine");
     INIT_TYPE(&_PyCoroWrapper_Type, "coroutine wrapper");
+    INIT_TYPE(&_PyInterpreterID_Type, "interpreter ID");
     return _Py_INIT_OK();
 
 #undef INIT_TYPE