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 .
+*/
+
+#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 .
+ */
+
+#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