diff --git a/stix2/test/test_utils_type_checks.py b/stix2/test/test_utils_type_checks.py
new file mode 100644
index 0000000..31d99eb
--- /dev/null
+++ b/stix2/test/test_utils_type_checks.py
@@ -0,0 +1,287 @@
+import pytest
+import stix2.utils
+
+
+###
+### Tests using types/behaviors common to STIX 2.0 and 2.1.
+###
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+@pytest.mark.parametrize(
+    "type_", [
+        "attack-pattern",
+        "campaign",
+        "course-of-action",
+        "identity",
+        "indicator",
+        "intrusion-set",
+        "malware",
+        "observed-data",
+        "report",
+        "threat-actor",
+        "tool",
+        "vulnerability"
+    ]
+)
+def test_is_sdo(type_, stix_version):
+    assert stix2.utils.is_sdo(type_, stix_version)
+
+    id_ = type_ + "--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert stix2.utils.is_sdo(id_, stix_version)
+
+    d = {
+        "type": type_
+    }
+    assert stix2.utils.is_sdo(d, stix_version)
+
+    assert stix2.utils.is_stix_type(
+        type_, stix_version, stix2.utils.STIXTypeClass.SDO
+    )
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+@pytest.mark.parametrize(
+    "type_", [
+        "relationship",
+        "sighting",
+        "marking-definition",
+        "bundle",
+        "language-content",
+        "ipv4-addr",
+        "foo"
+    ]
+)
+def test_is_not_sdo(type_, stix_version):
+    assert not stix2.utils.is_sdo(type_, stix_version)
+
+    id_ = type_ + "--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert not stix2.utils.is_sdo(id_, stix_version)
+
+    d = {
+        "type": type_
+    }
+    assert not stix2.utils.is_sdo(d, stix_version)
+
+    assert not stix2.utils.is_stix_type(
+        type_, stix_version, stix2.utils.STIXTypeClass.SDO
+    )
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+@pytest.mark.parametrize(
+    "type_", [
+        "artifact",
+        "autonomous-system",
+        "directory",
+        "domain-name",
+        "email-addr",
+        "email-message",
+        "file",
+        "ipv4-addr",
+        "ipv6-addr",
+        "mac-addr",
+        "mutex",
+        "network-traffic",
+        "process",
+        "software",
+        "url",
+        "user-account",
+        "windows-registry-key",
+        "x509-certificate"
+    ]
+)
+def test_is_sco(type_, stix_version):
+    assert stix2.utils.is_sco(type_, stix_version)
+
+    id_ = type_ + "--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert stix2.utils.is_sco(id_, stix_version)
+
+    d = {
+        "type": type_
+    }
+    assert stix2.utils.is_sco(d, stix_version)
+
+    assert stix2.utils.is_stix_type(
+        type_, stix_version, stix2.utils.STIXTypeClass.SCO
+    )
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+@pytest.mark.parametrize(
+    "type_", [
+        "identity",
+        "sighting",
+        "marking-definition",
+        "bundle",
+        "language-content",
+        "foo"
+    ]
+)
+def test_is_not_sco(type_, stix_version):
+    assert not stix2.utils.is_sco(type_, stix_version)
+
+    id_ = type_ + "--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert not stix2.utils.is_sco(id_, stix_version)
+
+    d = {
+        "type": type_
+    }
+    assert not stix2.utils.is_sco(d, stix_version)
+
+    assert not stix2.utils.is_stix_type(
+        type_, stix_version, stix2.utils.STIXTypeClass.SCO
+    )
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+@pytest.mark.parametrize(
+    "type_", [
+        "relationship",
+        "sighting"
+    ]
+)
+def test_is_sro(type_, stix_version):
+    assert stix2.utils.is_sro(type_, stix_version)
+
+    id_ = type_ + "--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert stix2.utils.is_sro(id_, stix_version)
+
+    d = {
+        "type": type_
+    }
+    assert stix2.utils.is_sro(d, stix_version)
+
+    assert stix2.utils.is_stix_type(
+        type_, stix_version, stix2.utils.STIXTypeClass.SRO
+    )
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+@pytest.mark.parametrize(
+    "type_", [
+        "identity",
+        "marking-definition",
+        "bundle",
+        "language-content",
+        "ipv4-addr",
+        "foo"
+    ]
+)
+def test_is_not_sro(type_, stix_version):
+    assert not stix2.utils.is_sro(type_, stix_version)
+
+    id_ = type_ + "--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert not stix2.utils.is_sro(id_, stix_version)
+
+    d = {
+        "type": type_
+    }
+    assert not stix2.utils.is_sro(d, stix_version)
+
+    assert not stix2.utils.is_stix_type(
+        type_, stix_version, stix2.utils.STIXTypeClass.SRO
+    )
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+def test_is_marking(stix_version):
+    assert stix2.utils.is_marking("marking-definition", stix_version)
+
+    id_ = "marking-definition--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert stix2.utils.is_marking(id_, stix_version)
+
+    d = {
+        "type": "marking-definition"
+    }
+    assert stix2.utils.is_marking(d, stix_version)
+
+    assert stix2.utils.is_stix_type(
+        "marking-definition", stix_version, "marking-definition"
+    )
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+@pytest.mark.parametrize(
+    "type_", [
+        "identity",
+        "bundle",
+        "language-content",
+        "ipv4-addr",
+        "foo"
+    ]
+)
+def test_is_not_marking(type_, stix_version):
+    assert not stix2.utils.is_marking(type_, stix_version)
+
+    id_ = type_ + "--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert not stix2.utils.is_marking(id_, stix_version)
+
+    d = {
+        "type": type_
+    }
+    assert not stix2.utils.is_marking(d, stix_version)
+
+    assert not stix2.utils.is_stix_type(
+        type_, stix_version, "marking-definition"
+    )
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+@pytest.mark.parametrize(
+    "type_", [
+        "identity",
+        "relationship",
+        "sighting",
+        "marking-definition",
+        "bundle",
+        "ipv4-addr"
+    ]
+)
+def test_is_object(type_, stix_version):
+    assert stix2.utils.is_object(type_, stix_version)
+
+    id_ = type_ + "--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert stix2.utils.is_object(id_, stix_version)
+
+    d = {
+        "type": type_
+    }
+    assert stix2.utils.is_object(d, stix_version)
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+def test_is_not_object(stix_version):
+    assert not stix2.utils.is_object("foo", stix_version)
+
+    id_ = "foo--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert not stix2.utils.is_object(id_, stix_version)
+
+    d = {
+        "type": "foo"
+    }
+    assert not stix2.utils.is_object(d, stix_version)
+
+
+@pytest.mark.parametrize("stix_version", ["2.0", "2.1"])
+def test_is_stix_type(stix_version):
+
+    assert not stix2.utils.is_stix_type(
+        "foo", stix_version, stix2.utils.STIXTypeClass.SDO, "foo"
+    )
+
+    assert stix2.utils.is_stix_type(
+        "bundle", stix_version, "foo", "bundle"
+    )
+
+    assert stix2.utils.is_stix_type(
+        "identity", stix_version,
+        stix2.utils.STIXTypeClass.SDO,
+        stix2.utils.STIXTypeClass.SRO
+    )
+
+    assert stix2.utils.is_stix_type(
+        "software", stix_version,
+        stix2.utils.STIXTypeClass.SDO,
+        stix2.utils.STIXTypeClass.SCO
+    )
diff --git a/stix2/test/v21/test_utils.py b/stix2/test/v21/test_utils.py
index 41bc087..940d1db 100644
--- a/stix2/test/v21/test_utils.py
+++ b/stix2/test/v21/test_utils.py
@@ -241,3 +241,40 @@ def test_find_property_index(object, tuple_to_find, expected_index):
 )
 def test_iterate_over_values(dict_value, tuple_to_find, expected_index):
     assert stix2.serialization._find_property_in_seq(dict_value.values(), *tuple_to_find) == expected_index
+
+
+# Only 2.1-specific types/behaviors tested here.
+@pytest.mark.parametrize(
+    "type_", [
+        "grouping",
+        "infrastructure",
+        "location",
+        "malware-analysis",
+        "note",
+        "opinion"
+    ]
+)
+def test_is_sdo(type_):
+    assert stix2.utils.is_sdo(type_, "2.1")
+
+    id_ = type_ + "--a12fa04c-6586-4128-8d1a-cfe0d1c081f5"
+    assert stix2.utils.is_sdo(id_, "2.1")
+
+    d = {
+        "type": type_
+    }
+    assert stix2.utils.is_sdo(d, "2.1")
+
+    assert stix2.utils.is_stix_type(
+        type_, "2.1", stix2.utils.STIXTypeClass.SDO
+    )
+
+
+def test_type_checks_language_content():
+    assert stix2.utils.is_object("language-content", "2.1")
+    assert not stix2.utils.is_sdo("language-content", "2.1")
+    assert not stix2.utils.is_sco("language-content", "2.1")
+    assert not stix2.utils.is_sro("language-content", "2.1")
+    assert stix2.utils.is_stix_type(
+        "language-content", "2.1", "language-content"
+    )