diff --git a/keyboards/montsinger/rebound/config.h b/keyboards/montsinger/rebound/config.h
new file mode 100644
index 0000000000..271664d96f
--- /dev/null
+++ b/keyboards/montsinger/rebound/config.h
@@ -0,0 +1,62 @@
+/*
+Copyright 2020 Ross Montsinger
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include "config_common.h"
+
+/* USB Device descriptor parameter */
+
+#define VENDOR_ID 0xFEED
+#define PRODUCT_ID 0x552F
+#define DEVICE_VER 0x0002
+#define MANUFACTURER Montsinger
+#define PRODUCT Rebound
+#define DESCRIPTION "A conjoined Let's Split"
+
+/* key matrix size */
+
+#define MATRIX_ROWS 4 
+#define MATRIX_COLS 12
+
+/*
+ * Keyboard Matrix Assignments
+ *
+ * Change this to how you wired your keyboard
+ * COLS: AVR pins used for columns, left to right
+ * ROWS: AVR pins used for rows, top to bottom
+ * DIODE_DIRECTION: COL2ROW = COL = Anode (+), ROW = Cathode (-, marked on 
+diode)
+ * ROW2COL = ROW = Anode (+), COL = Cathode (-, marked on diode)
+ *
+ */
+
+#define MATRIX_ROW_PINS { D1, B5, B2, B6 }
+#define MATRIX_COL_PINS { D0, D4, C6, D7, E6, B4, B3, B1, F7, F6, F5, F4 }
+#define UNUSED_PINS {  D2, D3 }
+
+/* COL2ROW, ROW2COL*/
+#define DIODE_DIRECTION ROW2COL
+
+/* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
+#define DEBOUNCE 5
+
+/* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
+#define LOCKING_SUPPORT_ENABLE
+/* Locking resynchronize hack */
+#define LOCKING_RESYNC_ENABLE
+
+/* Bootmagic Lite key configuration */
+// #define BOOTMAGIC_LITE_ROW 0
+// #define BOOTMAGIC_LITE_COLUMN 0
diff --git a/keyboards/montsinger/rebound/keymaps/default/keymap.c b/keyboards/montsinger/rebound/keymaps/default/keymap.c
new file mode 100644
index 0000000000..94d9ef91dc
--- /dev/null
+++ b/keyboards/montsinger/rebound/keymaps/default/keymap.c
@@ -0,0 +1,163 @@
+#include QMK_KEYBOARD_H
+
+// Each layer gets a name for readability, which is then used in the keymap matrix below.
+// The underscores don't mean anything - you can have a layer called STUFF or any other name.
+// Layer names don't all need to be of the same length, obviously, and you can also skip them
+// entirely and just use numbers.
+
+enum layer_names
+{
+  _QWERTY,
+  _COLEMAK,
+  _DVORAK,
+  _LOWER,
+  _RAISE,
+  _ADJUST
+};
+
+enum custom_keycodes {
+  QWERTY = SAFE_RANGE,
+  COLEMAK,
+  DVORAK
+};
+
+#define LOWER  MO(_LOWER)
+#define RAISE  MO(_RAISE)
+#define ADJUST MO(_ADJUST)
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+/* Qwerty
+ * ,-----------------------------------------------------------------------------------.
+ * | Tab  |   Q  |   W  |   E  |   R  |   T  |   Y  |   U  |   I  |   O  |   P  | Bksp |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | Esc  |   A  |   S  |   D  |   F  |   G  |   H  |   J  |   K  |   L  |   ;  |  "   |
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * | Shift|   Z  |   X  |   C  |   V  |   B  |   N  |   M  |   ,  |   .  |   /  |Enter |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * |Adjust| Ctrl | Alt  | GUI  |Lower |    Space    |Raise | Left | Down |  Up  |Right |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_QWERTY] = LAYOUT_ortho_4x12(
+   KC_TAB,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,    KC_BSPC, 
+   KC_ESC,  KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, KC_QUOT, 
+   KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_ENT , 
+   ADJUST,  KC_LCTL, KC_LALT, KC_LGUI, LOWER,   KC_SPC,  KC_SPC,  RAISE,   KC_LEFT, KC_DOWN, KC_UP,   KC_RGHT  
+),
+
+/* Colemak
+ * ,-----------------------------------------------------------------------------------.
+ * | Tab  |   Q  |   W  |   F  |   P  |   G  |   J  |   L  |   U  |   Y  |   ;  | Bksp |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | Esc  |   A  |   R  |   S  |   T  |   D  |   H  |   N  |   E  |   I  |   O  |  '   |
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * | Shift|   Z  |   X  |   C  |   V  |   B  |   K  |   M  |   ,  |   .  |   /  |Enter |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * |Adjust| Ctrl | Alt  | GUI  |Lower |Space |Space |Raise | Left | Down |  Up  |Right |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_COLEMAK] = LAYOUT_ortho_4x12(
+  KC_TAB,  KC_Q,    KC_W,    KC_F,    KC_P,    KC_G,    KC_J,    KC_L,    KC_U,    KC_Y,    KC_SCLN, KC_BSPC, 
+  KC_ESC,  KC_A,    KC_R,    KC_S,    KC_T,    KC_D,    KC_H,    KC_N,    KC_E,    KC_I,    KC_O,    KC_QUOT, 
+  KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_K,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_ENT , 
+  ADJUST,  KC_LCTL, KC_LALT, KC_LGUI, LOWER,   KC_SPC,  KC_SPC,  RAISE,   KC_LEFT, KC_DOWN, KC_UP,   KC_RGHT 
+),
+
+/* Dvorak
+ * ,-----------------------------------------------------------------------------------.
+ * | Tab  |   '  |   ,  |   .  |   P  |   Y  |   F  |   G  |   C  |   R  |   L  | Bksp |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | Esc  |   A  |   O  |   E  |   U  |   I  |   D  |   H  |   T  |   N  |   S  |  /   |
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * | Shift|   ;  |   Q  |   J  |   K  |   X  |   B  |   M  |   W  |   V  |   Z  |Enter |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * |Adjust| Ctrl | Alt  | GUI  |Lower |Space |Space |Raise | Left | Down |  Up  |Right |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_DVORAK] = LAYOUT_ortho_4x12(
+  KC_TAB,  KC_QUOT, KC_COMM, KC_DOT,  KC_P,    KC_Y,    KC_F,    KC_G,    KC_C,    KC_R,    KC_L,    KC_BSPC, 
+  KC_ESC,  KC_A,    KC_O,    KC_E,    KC_U,    KC_I,    KC_D,    KC_H,    KC_T,    KC_N,    KC_S,    KC_SLSH, 
+  KC_LSFT, KC_SCLN, KC_Q,    KC_J,    KC_K,    KC_X,    KC_B,    KC_M,    KC_W,    KC_V,    KC_Z,    KC_ENT , 
+  ADJUST,  KC_LCTL, KC_LALT, KC_LGUI, LOWER,   KC_SPC,  KC_SPC,  RAISE,   KC_LEFT, KC_DOWN, KC_UP,   KC_RGHT 
+),
+
+/* Lower
+ * ,-----------------------------------------------------------------------------------.
+ * |   ~  |   !  |   @  |   #  |   $  |   %  |   ^  |   &  |   *  |   (  |   )  | Del  |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | Del  |  F1  |  F2  |  F3  |  F4  |  F5  |  F6  |   _  |   +  |   {  |   }  |  |   |
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * |      |  F7  |  F8  |  F9  |  F10 |  F11 |  F12 |ISO ~ |ISO | |      |      |      |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * |      |      |      |      |      |             |      | Next | Vol- | Vol+ | Play |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_LOWER] = LAYOUT_ortho_4x12(
+  KC_TILD, KC_EXLM, KC_AT,   KC_HASH, KC_DLR,  KC_PERC, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_DEL, 
+  KC_DEL,  KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_UNDS, KC_PLUS, KC_LCBR, KC_RCBR, KC_PIPE, 
+  _______, KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,S(KC_NUHS),S(KC_NUBS),_______, _______, _______, 
+  _______, _______, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY 
+),
+
+/* Raise
+ * ,-----------------------------------------------------------------------------------.
+ * |   `  |   1  |   2  |   3  |   4  |   5  |   6  |   7  |   8  |   9  |   0  | Del  |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * | Del  |  F1  |  F2  |  F3  |  F4  |  F5  |  F6  |   -  |   =  |   [  |   ]  |  \   |
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * |      |  F7  |  F8  |  F9  |  F10 |  F11 |  F12 |ISO # |ISO / |      |      |      |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * |      |      |      |      |      |             |      | Next | Vol- | Vol+ | Play |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_RAISE] = LAYOUT_ortho_4x12(
+  KC_GRV,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_DEL, 
+  KC_DEL,  KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_MINS, KC_EQL,  KC_LBRC, KC_RBRC, KC_BSLS, 
+  _______, KC_F7,   KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  KC_NUHS, KC_NUBS, _______, _______, _______, 
+  _______, _______, _______, _______, _______, _______, _______, _______, KC_MNXT, KC_VOLD, KC_VOLU, KC_MPLY 
+),
+
+/* Adjust (Lower + Raise)
+ * ,-----------------------------------------------------------------------------------.
+ * |      | Reset|      |      |      |      |      |      |      |      |      |  Del |
+ * |------+------+------+------+------+-------------+------+------+------+------+------|
+ * |      |      |      |Aud on|Audoff|AGnorm|AGswap|Qwerty|Colemk|Dvorak|      |      |
+ * |------+------+------+------+------+------|------+------+------+------+------+------|
+ * |      |      |      |      |      |      |      |      |      |      |      |      |
+ * |------+------+------+------+------+------+------+------+------+------+------+------|
+ * |      |      |      |      |      |             |      |      |      |      |      |
+ * `-----------------------------------------------------------------------------------'
+ */
+[_ADJUST] =  LAYOUT_ortho_4x12(
+  _______, RESET,   _______, _______, _______, _______, _______, _______, _______, _______, _______, KC_DEL, 
+  _______, _______, _______, AU_ON,   AU_OFF,  AG_NORM, AG_SWAP, QWERTY,  COLEMAK, DVORAK,  _______, _______, 
+  _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, 
+  _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______, _______ 
+)
+
+
+};
+
+layer_state_t layer_state_set_user(layer_state_t state) {
+  return update_tri_layer_state(state, _LOWER, _RAISE, _ADJUST);
+}
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+  switch (keycode) {
+    case QWERTY:
+      if (record->event.pressed) {
+        set_single_persistent_default_layer(_QWERTY);
+      }
+      return false;
+    case COLEMAK:
+      if (record->event.pressed) {
+        set_single_persistent_default_layer(_COLEMAK);
+      }
+      return false;
+    case DVORAK:
+      if (record->event.pressed) {
+        set_single_persistent_default_layer(_DVORAK);
+      }
+      return false;
+  }
+  return true;
+}
diff --git a/keyboards/montsinger/rebound/readme.md b/keyboards/montsinger/rebound/readme.md
new file mode 100755
index 0000000000..d634408cc9
--- /dev/null
+++ b/keyboards/montsinger/rebound/readme.md
@@ -0,0 +1,15 @@
+# Rebound
+
+![Rebound](https://imgur.com/zMPhNmm.jpg)
+
+A conjoined-split 40% 4x12 ortholinear keyboard made and sold by Montsinger. [More info on Montsinger.net](https://montsinger.net).
+
+* Keyboard Maintainer: [Rossman360](https://github.com/rossman360)
+* Hardware Supported: Pro Micro, Elite-C
+* Hardware Availability: [Montsinger.net](https://montsinger.net)
+
+Make example for this keyboard (after setting up your build environment):
+
+    make montsinger/rebound:default
+
+See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs)
\ No newline at end of file
diff --git a/keyboards/montsinger/rebound/rebound.c b/keyboards/montsinger/rebound/rebound.c
new file mode 100644
index 0000000000..fbb10be713
--- /dev/null
+++ b/keyboards/montsinger/rebound/rebound.c
@@ -0,0 +1 @@
+#include "rebound.h"
diff --git a/keyboards/montsinger/rebound/rebound.h b/keyboards/montsinger/rebound/rebound.h
new file mode 100644
index 0000000000..0ba4c51ceb
--- /dev/null
+++ b/keyboards/montsinger/rebound/rebound.h
@@ -0,0 +1,39 @@
+/* Copyright 2020 Ross Montsinger
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once 
+
+#include "quantum.h"
+
+/* This is a shortcut to help you visually see your layout.
+ * The first section contains all of the arguments representing the 
+ * layout of the board and position of the keys.
+ *
+ * The second converts the arguments into a two-dimensional array which
+ * represents the switch matrix.
+ */
+ 
+#define LAYOUT_ortho_4x12( \
+    K00, K01, K02, K03, K04, K05, K06, K07, K08, K09, K0A, K0B, \
+    K10, K11, K12, K13, K14, K15, K16, K17, K18, K19, K1A, K1B, \
+    K20, K21, K22, K23, K24, K25, K26, K27, K28, K29, K2A, K2B,\
+    K30, K31, K32, K33, K34, K35, K36, K37, K38, K39, K3A, K3B\
+    ) { \
+  { K00, K01, K02, K03, K04, K05, K06, K07, K08, K09, K0A, K0B }, \
+  { K10, K11, K12, K13, K14, K15, K16, K17, K18, K19, K1A, K1B }, \
+  { K20, K21, K22, K23, K24, K25, K26, K27, K28, K29, K2A, K2B }, \
+  { K30, K31, K32, K33, K34, K35, K36, K37, K38, K39, K3A, K3B } \
+}
diff --git a/keyboards/montsinger/rebound/rules.mk b/keyboards/montsinger/rebound/rules.mk
new file mode 100644
index 0000000000..efa3133039
--- /dev/null
+++ b/keyboards/montsinger/rebound/rules.mk
@@ -0,0 +1,32 @@
+# MCU name
+MCU = atmega32u4
+
+# Bootloader selection
+#   Teensy       halfkay
+#   Pro Micro    caterina
+#   Atmel DFU    atmel-dfu
+#   LUFA DFU     lufa-dfu
+#   QMK DFU      qmk-dfu
+#   ATmega32A    bootloadHID
+#   ATmega328P   USBasp
+BOOTLOADER = atmel-dfu
+
+BOOTMAGIC_ENABLE = lite       # Virtual DIP switch configuration
+MOUSEKEY_ENABLE = yes       # Mouse keys
+EXTRAKEY_ENABLE = yes       # Audio control and System control
+CONSOLE_ENABLE = yes        # Console for debug
+COMMAND_ENABLE = yes        # Commands for debug and configuration
+# Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
+SLEEP_LED_ENABLE = no       # Breathing sleep LED during USB suspend
+# if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
+NKRO_ENABLE = no            # USB Nkey Rollover
+BACKLIGHT_ENABLE = no       # Enable keyboard backlight functionality
+RGBLIGHT_ENABLE = no        # Enable keyboard RGB underglow
+MIDI_ENABLE = no            # MIDI support
+BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
+AUDIO_ENABLE = no           # Audio output on port C6
+FAUXCLICKY_ENABLE = no      # Use buzzer to emulate clicky switches
+HD44780_ENABLE = no         # Enable support for HD44780 based LCDs
+
+LAYOUTS = ortho_4x12
+LAYOUTS_HAS_RGB=no