diff --git a/app/controllers/classrooms_controller.rb b/app/controllers/classrooms_controller.rb
index 2077184..dec88e9 100644
--- a/app/controllers/classrooms_controller.rb
+++ b/app/controllers/classrooms_controller.rb
@@ -1,16 +1,17 @@
 class ClassroomsController < AdminController
   before_action :set_classroom, only: %i[ edit update ]
 
-  # GET /classrooms/1/edit
   def edit
+    build_missing_program_enrollments
   end
-  # PATCH/PUT /classrooms/1 or /classrooms/1.json
+
   def update
     respond_to do |format|
       if @classroom.update(classroom_params)
         format.html { redirect_to school_students_url(@classroom.school), notice: "Classroom was successfully updated.", status: :see_other }
         format.json { render :show, status: :ok, location: @classroom }
       else
+        build_missing_program_enrollments
         format.html { render :edit, status: :unprocessable_entity }
         format.json { render json: @classroom.errors, status: :unprocessable_entity }
       end
@@ -18,13 +19,19 @@ def update
   end
 
   private
-    # Use callbacks to share common setup or constraints between actions.
     def set_classroom
       @classroom = Classroom.find(params.expect(:id))
     end
 
-    # Only allow a list of trusted parameters through.
+    def build_missing_program_enrollments
+      @classroom.classroom_programs.load unless @classroom.classroom_programs.loaded?
+      enrolled_ids = @classroom.classroom_programs.target.map(&:program_id).to_set
+      Program.order(:name).each do |program|
+        @classroom.classroom_programs.build(program: program) unless enrolled_ids.include?(program.id)
+      end
+    end
+
     def classroom_params
-      params.expect(classroom: [ :name, :teacher ])
+      params.expect(classroom: [ :name, :teacher, classroom_programs_attributes: [ [ :id, :program_id, :level, :_destroy ] ] ])
     end
 end
diff --git a/app/javascript/controllers/program_enrollment_controller.js b/app/javascript/controllers/program_enrollment_controller.js
new file mode 100644
index 0000000..ed9e670
--- /dev/null
+++ b/app/javascript/controllers/program_enrollment_controller.js
@@ -0,0 +1,11 @@
+import { Controller } from "@hotwired/stimulus"
+
+export default class extends Controller {
+  static targets = ["levelSection", "destroy"]
+
+  toggle(event) {
+    const enrolled = event.target.checked
+    this.levelSectionTarget.style.display = enrolled ? "" : "none"
+    this.destroyTarget.value = enrolled ? "0" : "1"
+  }
+}
diff --git a/app/models/classroom.rb b/app/models/classroom.rb
index 7e1ca13..d4ca41e 100644
--- a/app/models/classroom.rb
+++ b/app/models/classroom.rb
@@ -1,4 +1,19 @@
 class Classroom < ApplicationRecord
   belongs_to :school
   has_many :students
+  has_many :classroom_programs, dependent: :destroy
+  has_many :programs, through: :classroom_programs
+
+  accepts_nested_attributes_for :classroom_programs,
+    allow_destroy: true,
+    reject_if: proc { |attrs| attrs["id"].blank? && attrs["_destroy"] == "1" }
+
+  validate :at_least_one_active_program, on: :update
+
+  private
+
+  def at_least_one_active_program
+    active = classroom_programs.reject(&:marked_for_destruction?)
+    errors.add(:base, "must have at least one program enrolled") if active.empty?
+  end
 end
diff --git a/app/models/classroom_program.rb b/app/models/classroom_program.rb
new file mode 100644
index 0000000..99dc46c
--- /dev/null
+++ b/app/models/classroom_program.rb
@@ -0,0 +1,8 @@
+class ClassroomProgram < ApplicationRecord
+  belongs_to :classroom
+  belongs_to :program
+
+  enum :level, { basic: "basic", moderate: "moderate", advanced: "advanced" }, validate: true
+
+  validates :level, presence: true
+end
diff --git a/app/models/program.rb b/app/models/program.rb
new file mode 100644
index 0000000..c15e52c
--- /dev/null
+++ b/app/models/program.rb
@@ -0,0 +1,4 @@
+class Program < ApplicationRecord
+  has_many :classroom_programs, dependent: :destroy
+  has_many :classrooms, through: :classroom_programs
+end
diff --git a/app/views/classrooms/_form.html.erb b/app/views/classrooms/_form.html.erb
index 81cccc1..2b6fdd8 100644
--- a/app/views/classrooms/_form.html.erb
+++ b/app/views/classrooms/_form.html.erb
@@ -18,6 +18,30 @@
     <%= form.label :teacher, class: "label" %>
     <%= form.text_field :teacher, class: "input w-full" %>
 
+    <div class="flex flex-col gap-1">
+      <span class="label">Programs</span>
+      <%= form.fields_for :classroom_programs do |cp_form| %>
+        <% enrolled = cp_form.object.persisted? %>
+        <div class="flex items-center gap-3" data-controller="program-enrollment">
+          <%= cp_form.hidden_field :program_id %>
+          <%= cp_form.hidden_field :_destroy, value: enrolled ? "0" : "1", data: { program_enrollment_target: "destroy" } %>
+          <label class="flex items-center gap-2 cursor-pointer">
+            <input type="checkbox" class="checkbox checkbox-primary"
+                   <%= "checked" if enrolled %>
+                   autocomplete="off"
+                   data-action="change->program-enrollment#toggle">
+            <span class="label"><%= cp_form.object.program.name %></span>
+          </label>
+          <div data-program-enrollment-target="levelSection" <%= "style='display:none'" unless enrolled %>>
+            <%= cp_form.select :level,
+                  ClassroomProgram.levels.keys.map { |l| [l.humanize, l] },
+                  { include_blank: "Select level", selected: cp_form.object.level },
+                  class: "select select-bordered select-sm" %>
+          </div>
+        </div>
+      <% end %>
+    </div>
+
     <%= form.label :Link, class: "label" %>
     <%= link_to classroom_roster_url(classroom.uuid), classroom_roster_path(classroom.uuid), class: 'link' %>
 
diff --git a/db/migrate/20260516200133_create_programs.rb b/db/migrate/20260516200133_create_programs.rb
new file mode 100644
index 0000000..63d6dcc
--- /dev/null
+++ b/db/migrate/20260516200133_create_programs.rb
@@ -0,0 +1,19 @@
+class CreatePrograms < ActiveRecord::Migration[8.1]
+  def change
+    create_table :programs do |t|
+      t.string :name
+
+      t.timestamps
+    end
+
+    create_table :classroom_programs do |t|
+      t.references :classroom, null: false, foreign_key: true
+      t.references :program, null: false, foreign_key: true
+      t.string :level, null: false
+
+      t.timestamps
+    end
+
+    add_index :classroom_programs, [ :classroom_id, :program_id ], unique: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 4000b96..1d60635 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,18 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.1].define(version: 2026_04_29_230254) do
+ActiveRecord::Schema[8.1].define(version: 2026_05_16_200133) do
+  create_table "classroom_programs", force: :cascade do |t|
+    t.integer "classroom_id", null: false
+    t.datetime "created_at", null: false
+    t.string "level", null: false
+    t.integer "program_id", null: false
+    t.datetime "updated_at", null: false
+    t.index ["classroom_id", "program_id"], name: "index_classroom_programs_on_classroom_id_and_program_id", unique: true
+    t.index ["classroom_id"], name: "index_classroom_programs_on_classroom_id"
+    t.index ["program_id"], name: "index_classroom_programs_on_program_id"
+  end
+
   create_table "classrooms", force: :cascade do |t|
     t.datetime "created_at", null: false
     t.string "name"
@@ -22,6 +33,12 @@
     t.index ["uuid"], name: "index_classrooms_on_uuid", unique: true
   end
 
+  create_table "programs", force: :cascade do |t|
+    t.datetime "created_at", null: false
+    t.string "name"
+    t.datetime "updated_at", null: false
+  end
+
   create_table "schools", force: :cascade do |t|
     t.datetime "created_at", null: false
     t.string "name"
@@ -67,6 +84,8 @@
     t.index ["email_address"], name: "index_users_on_email_address", unique: true
   end
 
+  add_foreign_key "classroom_programs", "classrooms"
+  add_foreign_key "classroom_programs", "programs"
   add_foreign_key "classrooms", "schools"
   add_foreign_key "sessions", "users"
   add_foreign_key "student_sessions", "students"
diff --git a/db/seeds.rb b/db/seeds.rb
index 2e02363..0d353ea 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -1,5 +1,7 @@
 return unless Rails.env.development?
 
+programs = Program.create! [ { name: "Know Your Health" }, { name: "3D Wellness" } ]
+
 User.find_or_create_by!(email_address: "admin@example.com") do |user|
   user.name = "Admin"
   user.password = "password"
@@ -26,7 +28,12 @@ def build_student_attrs(overrides = {})
 grades = (1..12).to_a.sample(3)
 grades.each do |grade|
   classrooms = 2.times.map do |i|
-    school.classrooms.create!(name: "Classroom #{ i + 1 }", teacher: maybe { Faker::Name.name }, uuid: SecureRandom.urlsafe_base64(32))
+    classroom = school.classrooms.create!(name: "Classroom #{ i + 1 }", teacher: maybe { Faker::Name.name }, uuid: SecureRandom.urlsafe_base64(32))
+    assigned = Faker::Boolean.boolean ? [ programs.sample ] : programs
+    assigned.each do |program|
+      classroom.classroom_programs.create!(program: program, level: %w[basic moderate advanced].sample)
+    end
+    classroom
   end
   students = 10.times.map { |i| build_student_attrs(grade_level: grade, classroom_id: classrooms[i % 2].id) }
   school.students.create!(students)
diff --git a/test/controllers/classrooms_controller_test.rb b/test/controllers/classrooms_controller_test.rb
index a4fa5f6..da30fda 100644
--- a/test/controllers/classrooms_controller_test.rb
+++ b/test/controllers/classrooms_controller_test.rb
@@ -11,9 +11,86 @@ class ClassroomsControllerTest < ActionDispatch::IntegrationTest
     assert_response :success
   end
 
-  test "should update classroom" do
-    sign_in_as users(:admin)
-    patch classroom_url(@classroom), params: { classroom: { name: @classroom.name, teacher: @classroom.teacher } }
+  test "should update classroom name and teacher" do
+    patch classroom_url(@classroom), params: { classroom: { name: "Updated Name", teacher: "New Teacher" } }
+    assert_redirected_to school_students_url(@classroom.school)
+    assert_equal "Updated Name", @classroom.reload.name
+  end
+
+  test "should add a program enrollment" do
+    program = programs(:"3dw")
+
+    assert_difference "ClassroomProgram.count" do
+      patch classroom_url(@classroom), params: {
+        classroom: {
+          name: @classroom.name,
+          classroom_programs_attributes: [ { program_id: program.id, level: "moderate" } ]
+        }
+      }
+    end
+
+    assert_redirected_to school_students_url(@classroom.school)
+    assert @classroom.classroom_programs.exists?(program: program, level: "moderate")
+  end
+
+  test "should update an existing enrollment level" do
+    cp = classroom_programs(:one)
+
+    patch classroom_url(@classroom), params: {
+      classroom: {
+        name: @classroom.name,
+        classroom_programs_attributes: [ { id: cp.id, program_id: cp.program_id, level: "advanced" } ]
+      }
+    }
+
+    assert_redirected_to school_students_url(@classroom.school)
+    assert_equal "advanced", cp.reload.level
+  end
+
+  test "should remove an enrollment" do
+    cp = classroom_programs(:one)
+    # Add a second enrollment so the classroom still has one after removal
+    @classroom.classroom_programs.create!(program: programs(:"3dw"), level: "basic")
+
+    assert_difference "ClassroomProgram.count", -1 do
+      patch classroom_url(@classroom), params: {
+        classroom: {
+          name: @classroom.name,
+          classroom_programs_attributes: [ { id: cp.id, _destroy: "1" } ]
+        }
+      }
+    end
+
     assert_redirected_to school_students_url(@classroom.school)
   end
+
+  test "is invalid when removing all programs" do
+    cp = classroom_programs(:one)
+
+    assert_no_difference "ClassroomProgram.count" do
+      patch classroom_url(@classroom), params: {
+        classroom: {
+          name: @classroom.name,
+          classroom_programs_attributes: [ { id: cp.id, _destroy: "1" } ]
+        }
+      }
+    end
+
+    assert_response :unprocessable_entity
+  end
+
+  test "is invalid when a program is selected without a level" do
+    program = programs(:"3dw")
+
+    assert_no_difference "ClassroomProgram.count" do
+      patch classroom_url(@classroom), params: {
+        classroom: {
+          name: @classroom.name,
+          classroom_programs_attributes: [ { program_id: program.id, level: "" } ]
+        }
+      }
+    end
+
+    assert_response :unprocessable_entity
+  end
 end
diff --git a/test/controllers/students_controller_test.rb b/test/controllers/students_controller_test.rb
index f2ae2b3..08c7916 100644
--- a/test/controllers/students_controller_test.rb
+++ b/test/controllers/students_controller_test.rb
@@ -41,8 +41,7 @@ class StudentsControllerTest < ActionDispatch::IntegrationTest
   end
 
   test "can update a student's classroom" do
-    classroom = @student.classroom.dup
-    classroom.update! uuid: SecureRandom.urlsafe_base64(32), name: "New Classroom"
+    classroom = @school.classrooms.create!(name: "New Classroom", uuid: SecureRandom.urlsafe_base64(32))
     assert_changes -> { @student.reload.classroom_id } do
       patch student_url(@student), params: { student: { classroom_id: classroom.id } }
       assert_redirected_to student_url(@student)
diff --git a/test/fixtures/classroom_programs.yml b/test/fixtures/classroom_programs.yml
new file mode 100644
index 0000000..cad6043
--- /dev/null
+++ b/test/fixtures/classroom_programs.yml
@@ -0,0 +1,9 @@
+one:
+  classroom: one
+  program: kyh
+  level: basic
+
+two:
+  classroom: two
+  program: 3dw
+  level: moderate
diff --git a/test/fixtures/programs.yml b/test/fixtures/programs.yml
new file mode 100644
index 0000000..f5b4264
--- /dev/null
+++ b/test/fixtures/programs.yml
@@ -0,0 +1,7 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+kyh:
+  name: Know Your Health
+
+3dw:
+  name: 3D Wellness
diff --git a/test/models/classroom_test.rb b/test/models/classroom_test.rb
index 5f872f0..c529a33 100644
--- a/test/models/classroom_test.rb
+++ b/test/models/classroom_test.rb
@@ -1,7 +1,76 @@
 require "test_helper"
 
 class ClassroomTest < ActiveSupport::TestCase
-  # test "the truth" do
-  #   assert true
-  # end
+  test "creates enrollment via nested attributes" do
+    classroom = classrooms(:one)
+    program = programs(:"3dw")
+
+    assert_difference "ClassroomProgram.count" do
+      classroom.update!(
+        classroom_programs_attributes: [ { program_id: program.id, level: "advanced" } ]
+      )
+    end
+
+    assert classroom.classroom_programs.exists?(program: program, level: "advanced")
+  end
+
+  test "updates level via nested attributes" do
+    classroom = classrooms(:one)
+    cp = classroom_programs(:one)
+
+    classroom.update!(
+      classroom_programs_attributes: [ { id: cp.id, program_id: cp.program_id, level: "advanced" } ]
+    )
+
+    assert_equal "advanced", cp.reload.level
+  end
+
+  test "destroys enrollment via nested attributes" do
+    classroom = classrooms(:one)
+    cp = classroom_programs(:one)
+
+    # Add a second enrollment first so the classroom still has one after destruction
+    classroom.classroom_programs.create!(program: programs(:"3dw"), level: "basic")
+
+    assert_difference "ClassroomProgram.count", -1 do
+      classroom.update!(
+        classroom_programs_attributes: [ { id: cp.id, _destroy: "1" } ]
+      )
+    end
+  end
+
+  test "rejects new enrollment when checkbox is unchecked (_destroy: 1)" do
+    classroom = classrooms(:one)
+    program = programs(:"3dw")
+
+    assert_no_difference "ClassroomProgram.count" do
+      classroom.update!(
+        classroom_programs_attributes: [ { program_id: program.id, level: "basic", _destroy: "1" } ]
+      )
+    end
+  end
+
+  test "is invalid when a new enrollment has no level selected" do
+    classroom = classrooms(:one)
+    program = programs(:"3dw")
+
+    classroom.assign_attributes(
+      classroom_programs_attributes: [ { program_id: program.id, level: "" } ]
+    )
+
+    assert_not classroom.valid?
+    assert classroom.errors.any? { |e| e.attribute.to_s.include?("classroom_programs") }
+  end
+
+  test "is invalid when all programs are removed" do
+    classroom = classrooms(:one)
+    cp = classroom_programs(:one)
+
+    classroom.assign_attributes(
+      classroom_programs_attributes: [ { id: cp.id, _destroy: "1" } ]
+    )
+
+    assert_not classroom.valid?
+    assert_includes classroom.errors[:base], "must have at least one program enrolled"
+  end
 end
diff --git a/test/models/program_test.rb b/test/models/program_test.rb
new file mode 100644
index 0000000..1658794
--- /dev/null
+++ b/test/models/program_test.rb
@@ -0,0 +1,7 @@
+require "test_helper"
+
+class ProgramTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end