diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5894b83..a9c36a1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Removed
 * Dropped support for Python 3.9 [gh-118](https://github.com/IntelPython/mkl-service/pull/118)
+* Dropped support for `"ssse3"`, `"sse4_1"`, `"avx"`, `"avx512_mic"`, `"avx512_mic,strict"`, and `"avx512_mic_e1"` cbwr branches [gh-173](https://github.com/IntelPython/mkl-service/pull/173)
 
 ## [2.6.1] (11/25/2025)
 
diff --git a/mkl/_mkl_service.pxd b/mkl/_mkl_service.pxd
index 8acb4e4..ea22e1c 100644
--- a/mkl/_mkl_service.pxd
+++ b/mkl/_mkl_service.pxd
@@ -55,14 +55,9 @@ cdef extern from "mkl.h":
     int MKL_CBWR_AUTO
     int MKL_CBWR_COMPATIBLE
     int MKL_CBWR_SSE2
-    int MKL_CBWR_SSSE3
-    int MKL_CBWR_SSE4_1
     int MKL_CBWR_SSE4_2
-    int MKL_CBWR_AVX
     int MKL_CBWR_AVX2
-    int MKL_CBWR_AVX512_MIC
     int MKL_CBWR_AVX512
-    int MKL_CBWR_AVX512_MIC_E1
     int MKL_CBWR_AVX512_E1
 
     int MKL_CBWR_SUCCESS
@@ -77,13 +72,10 @@ cdef extern from "mkl.h":
     int MKL_ENABLE_AVX512_E2
     int MKL_ENABLE_AVX512_E3
     int MKL_ENABLE_AVX512_E4
-    int MKL_ENABLE_AVX512_MIC_E1
     int MKL_ENABLE_AVX512_E1
     int MKL_ENABLE_AVX512
-    int MKL_ENABLE_AVX512_MIC
     int MKL_ENABLE_AVX2
     int MKL_ENABLE_AVX2_E1
-    int MKL_ENABLE_AVX
     int MKL_ENABLE_SSE4_2
 
     # MPI Implementation Constants
diff --git a/mkl/_mkl_service.pyx b/mkl/_mkl_service.pyx
index b8600cb..3b59b08 100644
--- a/mkl/_mkl_service.pyx
+++ b/mkl/_mkl_service.pyx
@@ -677,17 +677,11 @@ cdef object __cbwr_set(branch=None) except *:
             "auto": mkl.MKL_CBWR_AUTO,
             "compatible": mkl.MKL_CBWR_COMPATIBLE,
             "sse2": mkl.MKL_CBWR_SSE2,
-            "ssse3": mkl.MKL_CBWR_SSSE3,
-            "sse4_1": mkl.MKL_CBWR_SSE4_1,
             "sse4_2": mkl.MKL_CBWR_SSE4_2,
-            "avx": mkl.MKL_CBWR_AVX,
             "avx2": mkl.MKL_CBWR_AVX2,
             "avx2,strict": mkl.MKL_CBWR_AVX2 | mkl.MKL_CBWR_STRICT,
-            "avx512_mic": mkl.MKL_CBWR_AVX512_MIC,
-            "avx512_mic,strict": mkl.MKL_CBWR_AVX512_MIC | mkl.MKL_CBWR_STRICT,
             "avx512": mkl.MKL_CBWR_AVX512,
             "avx512,strict": mkl.MKL_CBWR_AVX512 | mkl.MKL_CBWR_STRICT,
-            "avx512_mic_e1": mkl.MKL_CBWR_AVX512_MIC_E1,
             "avx512_e1": mkl.MKL_CBWR_AVX512_E1,
             "avx512_e1,strict": mkl.MKL_CBWR_AVX512_E1 | mkl.MKL_CBWR_STRICT,
         },
@@ -720,17 +714,11 @@ cdef inline __cbwr_get(cnr_const=None) except *:
             mkl.MKL_CBWR_AUTO: "auto",
             mkl.MKL_CBWR_COMPATIBLE: "compatible",
             mkl.MKL_CBWR_SSE2: "sse2",
-            mkl.MKL_CBWR_SSSE3: "ssse3",
-            mkl.MKL_CBWR_SSE4_1: "sse4_1",
             mkl.MKL_CBWR_SSE4_2: "sse4_2",
-            mkl.MKL_CBWR_AVX: "avx",
             mkl.MKL_CBWR_AVX2: "avx2",
             mkl.MKL_CBWR_AVX2 | mkl.MKL_CBWR_STRICT: "avx2,strict",
-            mkl.MKL_CBWR_AVX512_MIC: "avx512_mic",
-            mkl.MKL_CBWR_AVX512_MIC | mkl.MKL_CBWR_STRICT: "avx512_mic,strict",
             mkl.MKL_CBWR_AVX512: "avx512",
             mkl.MKL_CBWR_AVX512 | mkl.MKL_CBWR_STRICT: "avx512,strict",
-            mkl.MKL_CBWR_AVX512_MIC_E1: "avx512_mic_e1",
             mkl.MKL_CBWR_AVX512_E1: "avx512_e1",
             mkl.MKL_CBWR_AVX512_E1 | mkl.MKL_CBWR_STRICT: "avx512_e1,strict",
             mkl.MKL_CBWR_ERR_INVALID_INPUT: "err_invalid_input",
@@ -754,17 +742,11 @@ cdef object __cbwr_get_auto_branch() except *:
             mkl.MKL_CBWR_AUTO: "auto",
             mkl.MKL_CBWR_COMPATIBLE: "compatible",
             mkl.MKL_CBWR_SSE2: "sse2",
-            mkl.MKL_CBWR_SSSE3: "ssse3",
-            mkl.MKL_CBWR_SSE4_1: "sse4_1",
             mkl.MKL_CBWR_SSE4_2: "sse4_2",
-            mkl.MKL_CBWR_AVX: "avx",
             mkl.MKL_CBWR_AVX2: "avx2",
             mkl.MKL_CBWR_AVX2 | mkl.MKL_CBWR_STRICT: "avx2,strict",
-            mkl.MKL_CBWR_AVX512_MIC: "avx512_mic",
-            mkl.MKL_CBWR_AVX512_MIC | mkl.MKL_CBWR_STRICT: "avx512_mic,strict",
             mkl.MKL_CBWR_AVX512: "avx512",
             mkl.MKL_CBWR_AVX512 | mkl.MKL_CBWR_STRICT: "avx512,strict",
-            mkl.MKL_CBWR_AVX512_MIC_E1: "avx512_mic_e1",
             mkl.MKL_CBWR_AVX512_E1: "avx512_e1",
             mkl.MKL_CBWR_AVX512_E1 | mkl.MKL_CBWR_STRICT: "avx512_e1,strict",
             mkl.MKL_CBWR_SUCCESS: "success",
@@ -791,12 +773,9 @@ cdef object __enable_instructions(isa=None) except *:
             "avx512_e3": mkl.MKL_ENABLE_AVX512_E3,
             "avx512_e2": mkl.MKL_ENABLE_AVX512_E2,
             "avx512_e1": mkl.MKL_ENABLE_AVX512_E1,
-            "avx512_mic_e1": mkl.MKL_ENABLE_AVX512_MIC_E1,
             "avx512": mkl.MKL_ENABLE_AVX512,
-            "avx512_mic": mkl.MKL_ENABLE_AVX512_MIC,
             "avx2_e1": mkl.MKL_ENABLE_AVX2_E1,
             "avx2": mkl.MKL_ENABLE_AVX2,
-            "avx": mkl.MKL_ENABLE_AVX,
             "sse4_2": mkl.MKL_ENABLE_SSE4_2,
         },
     }
diff --git a/mkl/tests/test_mkl_service.py b/mkl/tests/test_mkl_service.py
index 22b2e60..7c9c97a 100644
--- a/mkl/tests/test_mkl_service.py
+++ b/mkl/tests/test_mkl_service.py
@@ -219,21 +219,15 @@ def check_cbwr(branch, cnr_const):
     "auto",
     "compatible",
     "sse2",
-    "ssse3",
-    "sse4_1",
     "sse4_2",
-    "avx",
     "avx2",
-    "avx512_mic",
     "avx512",
-    "avx512_mic_e1",
     "avx512_e1",
 ]
 
 
 strict = [
     "avx2,strict",
-    "avx512_mic,strict",
     "avx512,strict",
     "avx512_e1,strict",
 ]
@@ -253,26 +247,14 @@ def test_cbwr_get_auto_branch():
     mkl.cbwr_get_auto_branch()
 
 
-def test_enable_instructions_avx512_mic_e1():
-    mkl.enable_instructions("avx512_mic_e1")
-
-
 def test_enable_instructions_avx512():
     mkl.enable_instructions("avx512")
 
 
-def test_enable_instructions_avx512_mic():
-    mkl.enable_instructions("avx512_mic")
-
-
 def test_enable_instructions_avx2():
     mkl.enable_instructions("avx2")
 
 
-def test_enable_instructions_avx():
-    mkl.enable_instructions("avx")
-
-
 def test_enable_instructions_sse4_2():
     mkl.enable_instructions("sse4_2")