--- a/taskcluster/ci/test/tests.yml
+++ b/taskcluster/ci/test/tests.yml
@@ -104,16 +104,20 @@ cppunit:
                             - unittests/win_taskcluster_unittest.py
                         macosx.*:
                             - unittests/mac_unittest.py
                         linux.*:
                             - unittests/linux_unittest.py
                             - remove_executables.py
                 extra-options:
                     - --cppunittest-suite=cppunittest
+    tier:
+        by-test-platform:
+            windows10-64-asan.*: 3
+            default: default
 
 crashtest:
     description: "Crashtest run"
     suite: reftest/crashtest
     treeherder-symbol: tc-R(C)
     instance-size:
         by-test-platform:
             android.*: xlarge
@@ -153,16 +157,17 @@ crashtest:
                         linux.*:
                             - unittests/linux_unittest.py
                             - remove_executables.py
                 extra-options:
                     - --reftest-suite=crashtest
     tier:
         by-test-platform:
             linux64-qr/.*: 1
+            windows10-64-asan.*: 3
             default: default
 
 firefox-ui-functional-local:
     description: "Firefox-ui-tests functional run"
     suite: "firefox-ui/functional local"
     treeherder-symbol: tc-Fxfn-l(en-US)
     max-run-time: 5400
     mozharness:
@@ -175,16 +180,20 @@ firefox-ui-functional-local:
                     - firefox_ui_tests/taskcluster.py
                     - firefox_ui_tests/taskcluster_mac.py
                 linux.*:
                     - firefox_ui_tests/taskcluster.py
                     - remove_executables.py
         extra-options:
             - "--tag"
             - "local"
+    tier:
+        by-test-platform:
+            windows10-64-asan.*: 3
+            default: default
 
 firefox-ui-functional-remote:
     description: "Firefox-ui-tests functional run"
     suite: "firefox-ui/functional remote"
     treeherder-symbol: tc-Fxfn-r(en-US)
     max-run-time: 5400
     tier: 2
     mozharness:
@@ -197,16 +206,20 @@ firefox-ui-functional-remote:
                     - firefox_ui_tests/taskcluster.py
                     - firefox_ui_tests/taskcluster_mac.py
                 linux.*:
                     - firefox_ui_tests/taskcluster.py
                     - remove_executables.py
         extra-options:
             - "--tag"
             - "remote"
+    tier:
+        by-test-platform:
+            windows10-64-asan.*: 3
+            default: default
 
 geckoview:
     description: "Geckoview run"
     suite: geckoview
     treeherder-symbol: tc(gv)
     instance-size: xlarge
     loopback-video: true
     e10s: false
@@ -244,16 +257,17 @@ gtest:
                     - unittests/linux_unittest.py
                     - remove_executables.py
         extra-options:
             - --gtest-suite=gtest
     tier:
         by-test-platform:
             windows7-32-pgo.*: 3
             windows10-64-pgo.*: 3
+            windows10-64-asan.*: 3
             default: default
 
 jittest:
     description: "JIT Test run"
     suite: jittest/jittest-chunked
     treeherder-symbol: tc(Jit)
     e10s: false
     run-on-projects:
@@ -283,16 +297,20 @@ jittest:
                     - unittests/linux_unittest.py
                     - remove_executables.py
         extra-options:
             - --jittest-suite=jittest-chunked
     when:
         files-changed:
             - js/src/**
             - js/public/**
+    tier:
+        by-test-platform:
+            windows10-64-asan.*: 3
+            default: default
 
 jsreftest:
     description: "JS Reftest run"
     suite: reftest/jsreftest
     treeherder-symbol: tc-R(J)
     instance-size:
         by-test-platform:
             android.*: xlarge
@@ -341,16 +359,17 @@ jsreftest:
                     - --reftest-suite=jsreftest
     when:
         files-changed:
             - js/src/**
             - js/public/**
     tier:
         by-test-platform:
             linux64-qr/.*: 1
+            windows10-64-asan.*: 3
             default: default
 
 marionette:
     description: "Marionette unittest run"
     suite: marionette
     treeherder-symbol: tc(Mn)
     max-run-time:
         by-test-platform:
@@ -358,16 +377,17 @@ marionette:
             default: 5400
     instance-size:
         by-test-platform:
             android.*: xlarge
             default: default
     tier:
         by-test-platform:
             android.*: 2
+            windows10-64-asan.*: 3
             default: default
     chunks:
         by-test-platform:
             android.*: 10
             default: 1
     mozharness:
         by-test-platform:
             android.*:
@@ -392,33 +412,36 @@ marionette:
                             - remove_executables.py
 
 marionette-headless:
     description: "Marionette headless unittest run"
     suite: marionette
     treeherder-symbol: tc(MnH)
     max-run-time: 5400
     instance-size: default
-    tier: default
     chunks: 1
     mozharness:
         script: marionette.py
         no-read-buildbot-config: true
         config:
             by-test-platform:
                 windows.*:
                     - marionette/windows_taskcluster_config.py
                 macosx.*:
                     - marionette/prod_config.py
                     - marionette/mac_taskcluster_config.py
                 default:
                     - marionette/prod_config.py
                     - remove_executables.py
         extra-options:
             - --headless
+    tier:
+        by-test-platform:
+            windows10-64-asan.*: 3
+            default: default
 
 mochitest:
     description: "Mochitest plain run"
     suite:
         by-test-platform:
             linux64-jsdcov/opt: mochitest/plain-chunked-coverage
             default: mochitest/plain-chunked
     treeherder-symbol: tc-M()
@@ -452,16 +475,17 @@ mochitest:
         by-test-platform:
             linux.*-stylo.*: ['autoland', 'mozilla-central', 'try']
             macosx64-stylo/.*: ['mozilla-central', 'try']
             windows7-32-stylo.*: ['autoland', 'mozilla-central', 'try']
             default: built-projects
     tier:
         by-test-platform:
             macosx64-stylo/.*: 2
+            windows10-64-asan.*: 3
             default: default
     mozharness:
         by-test-platform:
             android.*:
                 mochitest-flavor: plain
                 script: android_emulator_unittest.py
                 no-read-buildbot-config: true
                 config:
@@ -520,16 +544,17 @@ mochitest-a11y:
                     - remove_executables.py
         extra-options:
             - --mochitest-suite=a11y
     tier:
         by-test-platform:
             .*-stylo.*: 2
             linux32-stylo/debug: 3
             linux64-stylo/debug: 3
+            windows10-64-asan.*: 3
             default: default
 
 mochitest-browser-chrome:
     description: "Mochitest browser-chrome run"
     suite:
         by-test-platform:
             linux64-jsdcov/opt: mochitest/browser-chrome-coverage
             default: mochitest/browser-chrome-chunked
@@ -596,16 +621,17 @@ mochitest-browser-chrome:
     instance-size:
         by-test-platform:
             linux64-jsdcov/opt: xlarge
             default: legacy
     allow-software-gl-layers: false
     tier:
         by-test-platform:
             .*-stylo.*: 2
+            windows10-64-asan.*: 3
             default: default
 
 mochitest-browser-screenshots:
     description: "Mochitest Browser Screenshots"
     suite: mochitest/browser-chrome-screenshots
     treeherder-symbol: tc-M(ss)
     loopback-video: true
     run-on-projects:
@@ -809,16 +835,20 @@ mochitest-devtools-chrome:
                     - --mochitest-suite=mochitest-devtools-chrome-chunked
     instance-size:
         by-test-platform:
             # Bug 1361476 - try xlarge on asan to see if it avoids OOM
             linux64-asan/opt: xlarge
             default: default
     # Bug 1296086: high number of intermittents observed with software GL and large instances
     allow-software-gl-layers: false
+    tier:
+        by-test-platform:
+            windows10-64-asan.*: 3
+            default: default
 
 mochitest-gpu:
     description: "Mochitest GPU run"
     suite: mochitest/gpu
     treeherder-symbol: tc-M(gpu)
     loopback-video: true
     virtualization: virtual-with-gpu
     run-on-projects:
@@ -865,16 +895,17 @@ mochitest-gpu:
                             - unittests/linux_unittest.py
                             - remove_executables.py
                 extra-options:
                     - --mochitest-suite=plain-gpu,chrome-gpu,browser-chrome-gpu
     tier:
         by-test-platform:
             linux64-qr/.*: 1
             macosx64-stylo/.*: 2
+            windows10-64-asan.*: 3
             default: default
 
 mochitest-jetpack:
     description: "Mochitest jetpack run"
     suite: mochitest/jetpack-package
     treeherder-symbol: tc-M(JP)
     loopback-video: true
     e10s: false
@@ -890,16 +921,20 @@ mochitest-jetpack:
                     - unittests/win_taskcluster_unittest.py
                 macosx.*:
                     - unittests/mac_unittest.py
                 linux.*:
                     - unittests/linux_unittest.py
                     - remove_executables.py
         extra-options:
             - --mochitest-suite=jetpack-package
+    tier:
+        by-test-platform:
+            windows10-64-asan.*: 3
+            default: default
 
 mochitest-media:
     description: "Mochitest media run"
     suite: mochitest/mochitest-media
     treeherder-symbol: tc-M(mda)
     max-run-time: 5400
     loopback-video: true
     instance-size:
@@ -955,16 +990,17 @@ mochitest-media:
                             - unittests/linux_unittest.py
                             - remove_executables.py
                 extra-options:
                     - --mochitest-suite=mochitest-media
     tier:
         by-test-platform:
             linux64-qr/.*: 1
             macosx64-stylo/.*: 2
+            windows10-64-asan.*: 3
             default: default
 
 mochitest-valgrind:
     description: "Mochitest plain Valgrind run"
     suite: mochitest/valgrind-plain
     treeherder-symbol: tc-M-V()
     run-on-projects: []
     tier: 3
@@ -1056,16 +1092,17 @@ mochitest-webgl:
                             - unittests/linux_unittest.py
                             - remove_executables.py
                 extra-options:
                     - --mochitest-suite=mochitest-gl
     tier:
         by-test-platform:
             linux64-qr/.*: 1
             macosx64-stylo/.*: 2
+            windows10-64-asan.*: 3
             default: default
 
 reftest:
     description: "Reftest run"
     suite: reftest/reftest
     treeherder-symbol: tc-R(R)
     run-on-projects:
         by-test-platform:
@@ -1130,16 +1167,17 @@ reftest:
                         linux.*:
                             - unittests/linux_unittest.py
                             - remove_executables.py
                 extra-options:
                     - --reftest-suite=reftest
     tier:
         by-test-platform:
             linux64-qr/.*: 1
+            windows10-64-asan.*: 3
             default: default
 
 reftest-gpu:
     description: "Reftest GPU run"
     suite: reftest/reftest-gpu
     treeherder-symbol: tc-R(Rg)
     run-on-projects:
         by-test-platform:
@@ -1211,16 +1249,20 @@ reftest-no-accel:
                     - unittests/win_taskcluster_unittest.py
                 macosx.*:
                     - unittests/mac_unittest.py
                 linux.*:
                     - unittests/linux_unittest.py
                     - remove_executables.py
         extra-options:
             - --reftest-suite=reftest-no-accel
+    tier:
+        by-test-platform:
+            windows10-64-asan.*: 3
+            default: default
 
 reftest-stylo:
     description: "Reftest run for Stylo"
     suite: reftest/reftest-stylo
     treeherder-symbol: tc-R(Rs)
     virtualization: virtual-with-gpu
     chunks: 16
     run-on-projects:
@@ -2329,8 +2371,12 @@ xpcshell:
                             - --xpcshell-suite=xpcshell-coverage
                         default:
                             - --xpcshell-suite=xpcshell
                 requires-signed-builds:
                     by-test-platform:
                         windows10-64-asan/opt: false    # No XPCShell on ASAN yet
                         windows.*: true
                         default: false
+    tier:
+        by-test-platform:
+            windows10-64-asan.*: 3
+            default: default