diff --git a/Gemfile b/Gemfile
index 1615206c4..aa35c3c6d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,6 +4,7 @@ ruby file: '.ruby-version'
 gem 'rails', '~> 8.1.2' # LOCKED: It is Rails.
 # The original asset pipeline for Rails [https://github.com/rails/sprockets-rails]
 gem 'sprockets-rails'
+gem 'coffee-script' # LOCKED: Added because Sprockets autoloads it when seeing .coffee files in the asset pipeline. Can be removed when that does not happen.
 
 gem 'amazing_print' # colourful output (suggested by rails_semantic_logger)
 gem 'rails_semantic_logger' # condense log lines: https://github.com/codebar/planner/issues/2339
@@ -23,7 +24,6 @@ gem 'friendly_id'
 gem 'haml'
 gem 'high_voltage'
 gem 'jquery-rails'
-gem 'jquery-ui-rails'
 
 # Use Active Storage variant
 gem 'image_processing'
@@ -37,7 +37,6 @@ gem 'pickadate-rails'
 gem 'premailer-rails'
 
 gem 'pundit'
-gem 'rails4-autocomplete'
 gem 'reline' # LOCKED: Added because of readline is not part of Ruby 3.5.0
 gem 'rolify'
 # Use Sass to process CSS
diff --git a/Gemfile.lock b/Gemfile.lock
index 02e8d2018..af7255890 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -154,6 +154,10 @@ GEM
       logger (~> 1.5)
     cocoon (1.2.15)
     coderay (1.1.3)
+    coffee-script (2.4.1)
+      coffee-script-source
+      execjs
+    coffee-script-source (1.12.2)
     commonmarker (2.6.3-aarch64-linux)
     commonmarker (2.6.3-arm64-darwin)
     commonmarker (2.6.3-x86_64-darwin)
@@ -253,8 +257,6 @@ GEM
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
-    jquery-ui-rails (6.0.1)
-      railties (>= 3.2.16)
     json (2.18.0)
     jwt (2.7.1)
     language_server-protocol (3.17.0.5)
@@ -428,8 +430,6 @@ GEM
     rails-html-sanitizer (1.6.2)
       loofah (~> 2.21)
       nokogiri (>= 1.15.7, != 1.16.7, != 1.16.6, != 1.16.5, != 1.16.4, != 1.16.3, != 1.16.2, != 1.16.1, != 1.16.0.rc1, != 1.16.0)
-    rails4-autocomplete (1.1.1)
-      rails (>= 3.0)
     rails_semantic_logger (4.19.0)
       rack
       railties (>= 5.1)
@@ -620,6 +620,7 @@ DEPENDENCIES
   carrierwave
   carrierwave-aws (~> 1.6)
   cocoon
+  coffee-script
   commonmarker
   csv
   database_cleaner
@@ -641,7 +642,6 @@ DEPENDENCIES
   importmap-rails
   irb
   jquery-rails
-  jquery-ui-rails
   launchy
   letter_opener
   listen (~> 3.10)
@@ -664,7 +664,6 @@ DEPENDENCIES
   rack-mini-profiler (~> 4.0)
   rails (~> 8.1.2)
   rails-html-sanitizer (~> 1.6.2)
-  rails4-autocomplete
   rails_semantic_logger
   reline
   rolify
diff --git a/app/assets/javascripts/application.js b/app/assets/javascripts/application.js
index a020fb295..020136fe1 100644
--- a/app/assets/javascripts/application.js
+++ b/app/assets/javascripts/application.js
@@ -15,8 +15,6 @@
 //= require bootstrap
 //= require rails-ujs
 //= require activestorage
-//= require jquery-ui
-//= require autocomplete-rails
 //= require chosen.jquery
 //= require 'jsimple-star-rating.min.js'
 //= require pickadate/picker
diff --git a/app/assets/stylesheets/application.scss b/app/assets/stylesheets/application.scss
index 82b19730d..54e9f854d 100644
--- a/app/assets/stylesheets/application.scss
+++ b/app/assets/stylesheets/application.scss
@@ -15,7 +15,6 @@
  *= require pickadate/classic.date
  *= require pickadate/classic.time
  *= require chosen
- *= require jquery-ui
  */
 
 @import "partials/colors";
diff --git a/app/controllers/members_controller.rb b/app/controllers/members_controller.rb
index 7f8b2264a..957162d9e 100644
--- a/app/controllers/members_controller.rb
+++ b/app/controllers/members_controller.rb
@@ -5,8 +5,6 @@ class MembersController < ApplicationController
   before_action :authenticate_member!, only: %i[edit step2 profile]
   before_action :suppress_notices, only: %i[step2]
 
-  autocomplete :skill, :name, class_name: 'ActsAsTaggableOn::Tag'
-
   def new
     @page_title = 'Sign up'
   end
diff --git a/config/routes.rb b/config/routes.rb
index 554bc442a..fc6dc3893 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -25,10 +25,6 @@
     resource :details, only: %i[edit update]
   end
 
-  resource :members do
-    get :autocomplete_skill_name, on: :collection
-  end
-
   get '/profile' => 'members#profile', as: :profile
 
   resources :subscriptions, only: %i[index create]
diff --git a/docs/rails4-autocomplete-investigation.md b/docs/rails4-autocomplete-investigation.md
new file mode 100644
index 000000000..d5ce1bbd6
--- /dev/null
+++ b/docs/rails4-autocomplete-investigation.md
@@ -0,0 +1,279 @@
+# rails4-autocomplete Investigation
+
+**Issue:** [#2445 - rails4-autocomplete removal or refactor](https://github.com/codebar/planner/issues/2445)
+
+**Investigation Date:** February 8, 2026
+
+**Summary:** The rails4-autocomplete gem (last updated April 2014) was accidentally broken during a Bootstrap 5 migration in April 2022 and has been non-functional for nearly 3 years. All infrastructure remains in place but is unused.
+
+## Current State
+
+### Where It's Referenced
+
+1. **Gemfile (line 40)**
+   ```ruby
+   gem 'rails4-autocomplete'
+   ```
+
+2. **Gemfile.lock**
+   - Version: 1.1.1 (last updated April 10, 2014 - 12 years ago)
+
+3. **Controller (`app/controllers/members_controller.rb:8`)**
+   ```ruby
+   autocomplete :skill, :name, class_name: 'ActsAsTaggableOn::Tag'
+   ```
+
+4. **Routes (`config/routes.rb:29`)**
+   ```ruby
+   get :autocomplete_skill_name, on: :collection
+   ```
+
+5. **JavaScript (`app/assets/javascripts/application.js:19`)**
+   ```javascript
+   //= require autocomplete-rails
+   ```
+
+6. **View (`app/views/members/_new.html.haml:22`)**
+   ```haml
+   = f.input :skill_list, input_html: { value: @member.skill_list.join(", ") }
+   ```
+
+### Why It's Not Working
+
+The view uses a plain `f.input :skill_list` field, but rails4-autocomplete requires using special helper methods like `autocomplete_field_tag` or specifying `as: :autocomplete` in the form input options.
+
+The current implementation renders a regular text input without:
+- The `as: :autocomplete` parameter
+- The `url: autocomplete_skill_name_members_path` parameter
+- Any `data-autocomplete` attributes
+- JavaScript bindings to trigger autocomplete
+
+The endpoint `/members/autocomplete_skill_name` exists but has never been wired up to the current frontend.
+
+## Historical Timeline
+
+### Phase 1: Initial Skills Feature (August 24, 2015)
+
+**Commit:** `185eddd3` by Margo Urey
+
+Added the basic skills feature:
+- Installed `acts-as-taggable-on` gem
+- Added migrations for tagging tables
+- Added `skill_list` field to member form
+- Field was a **plain text input** with manual comma-separated entry
+
+Form code:
+```haml
+= f.input :skill_list, label: "Skills, enter as a comma separated list"
+```
+
+### Phase 2: Autocomplete Added (September 25, 2015)
+
+**Commit:** `92f6df774c84803052496265dc3aff363530572c` by Margo Urey
+
+Enhanced the feature with autocomplete:
+
+**Changes:**
+- Added `rails4-autocomplete` gem (v1.1.1)
+- Added `jquery-ui-rails` gem (~> 5.0.0)
+- Modified form to use autocomplete:
+
+```haml
+= f.input :skill_list,
+  label: "Skills, enter as a comma separated list",
+  url: autocomplete_skill_name_members_path,
+  as: :autocomplete,
+  input_html: {'data-delimiter' => ','}
+```
+
+- Added controller method: `autocomplete :skill, :name, class_name: 'ActsAsTaggableOn::Tag'`
+- Added route: `get :autocomplete_skill_name, on: :collection`
+- Added JavaScript requires: `jquery-ui` and `autocomplete-rails`
+- Added CSS: `jquery-ui` stylesheet
+
+**Status:** ✅ Autocomplete was fully functional at this point
+
+### Phase 3: Accidental Removal (April 15, 2022)
+
+**Commit:** `b3cbd73070a05870e0c451eab9df31daf364ec9a` by Kriszta Matyi
+
+**PR:** [#1745 - Migrate member (public) forms to Bootstrap 5 classes](https://github.com/codebar/planner/pull/1745)
+
+**Merged:** May 6, 2022
+
+During Bootstrap 5 migration:
+- Deleted `app/views/members/_form.html.haml` entirely
+- Rewrote form in `_new.html.haml` from scratch
+- Lost the autocomplete parameters:
+
+```haml
+# Before (working):
+= f.input :skill_list,
+  label: 'Skills, enter as a comma separated list',
+  url: autocomplete_skill_name_members_path,
+  as: :autocomplete,
+  input_html: {'data-delimiter' => ','}
+
+# After (broken):
+= f.input :skill_list,
+  label: 'Skills, enter as a comma separated list',
+  input_html: { value: @member.skill_list.join(", ") }
+```
+
+**What Remained:**
+- rails4-autocomplete gem (zombie dependency)
+- Controller autocomplete method (unused)
+- Route definition (dead endpoint)
+- JavaScript requires (loaded but never invoked)
+
+**Status:** ❌ Autocomplete has been broken ever since (nearly 3 years)
+
+## Why This Went Unnoticed
+
+1. **No Tests:** Zero test coverage for autocomplete functionality
+2. **No Monitoring:** No error tracking since the endpoint is simply never called
+3. **Silent Degradation:** Form still works, just without autocomplete suggestions
+4. **Limited Usage:** Only affects coaches editing their skill list
+5. **Manual Entry Works:** Users can still enter comma-separated skills
+
+## Technical Debt Assessment
+
+### The Gem: rails4-autocomplete
+
+- **Last Updated:** April 10, 2014 (12 years ago)
+- **Rails Version:** Designed for Rails 4.x
+- **Current Rails:** Application is on Rails 8.1.2
+- **Maintenance:** Abandoned, no security updates
+- **Dependencies:** Requires jQuery-UI (also legacy)
+
+### The Infrastructure
+
+**Dead Code:**
+- Gem dependency (unused)
+- Controller method (never called)
+- Route (dead endpoint)
+- JavaScript asset (loaded but inactive)
+- jQuery-UI dependency (partially for this feature)
+
+**Still Referenced:**
+- `skill_list` field works without autocomplete
+- Tags stored in `acts-as-taggable-on` tables
+- Model scopes: `Member.with_skill(skill_name)`
+
+## Recommendations
+
+### Option 1: Complete Removal (Recommended)
+
+Remove all autocomplete infrastructure since it's been non-functional for 3 years with no user complaints.
+
+**Benefits:**
+- Removes unmaintained dependency
+- Cleans up dead code
+- Simplifies asset pipeline
+- No functionality loss (already broken)
+
+**To Remove:**
+- Gem: `rails4-autocomplete` from Gemfile
+- Gem: `jquery-ui-rails` from Gemfile (confirmed single-purpose dependency, see below)
+- Controller: `autocomplete :skill, :name, class_name: 'ActsAsTaggableOn::Tag'` line
+- Route: `get :autocomplete_skill_name, on: :collection`
+- JavaScript: `//= require autocomplete-rails` line
+- JavaScript: `//= require jquery-ui` line
+- CSS: `*= require jquery-ui` line
+
+**To Keep:**
+- `acts-as-taggable-on` gem (still actively used)
+- `skill_list` field (works with manual entry)
+- Member model tagging functionality
+
+### Option 2: Restore with Modern Alternative
+
+If autocomplete is deemed valuable, reimplement using modern tools.
+
+**Options:**
+- [Stimulus Autocomplete](https://github.com/afcapel/stimulus-autocomplete)
+- [TomSelect](https://tom-select.js.org/) (modern replacement for Chosen/Select2)
+- HTML5 `<datalist>` element (native browser autocomplete)
+
+**Considerations:**
+- Requires development effort
+- Needs testing coverage
+- User benefit unclear (no requests for 3 years)
+- May conflict with existing Stimulus/Turbo setup
+
+## Evidence
+
+### Git Commits
+
+```bash
+# Added autocomplete (Sep 25, 2015)
+git show 92f6df774c84803052496265dc3aff363530572c
+
+# Broke autocomplete (Apr 15, 2022)
+git show b3cbd73070a05870e0c451eab9df31daf364ec9a
+
+# Original skill feature (Aug 24, 2015)
+git show 185eddd3
+```
+
+### Testing Locally
+
+The endpoint exists but returns empty since it's never configured on the frontend:
+
+```bash
+curl http://localhost:3000/members/autocomplete_skill_name?term=ruby
+# Returns: []
+```
+
+The form field renders as a plain `<input type="text">` with no autocomplete attributes.
+
+## jquery-ui-rails Analysis
+
+### Investigation (February 8, 2026)
+
+**Question:** Can jquery-ui-rails be safely removed?
+
+**Answer:** Yes, with 95%+ confidence.
+
+**Evidence:**
+- Added in the same commit as rails4-autocomplete (Sep 25, 2015, commit `92f6df77`)
+- Added exclusively for the autocomplete feature
+- Comprehensive code search found **zero usage**:
+  - No jQuery UI JavaScript methods (`.datepicker()`, `.autocomplete()`, `.sortable()`, etc.)
+  - No jQuery UI CSS classes (`ui-widget`, `ui-state-*`, etc.)
+  - No data attributes for jQuery UI
+  - No dynamic JavaScript generating jQuery UI code
+- **Bundle size impact**: ~120KB saved from production assets
+- No other gems depend on it (checked chosen-rails, pickadate-rails)
+- The app uses alternatives:
+  - pickadate-rails for date picking
+  - chosen-rails for select boxes
+  - Bootstrap 5 for UI components
+
+**Risk Assessment:**
+- **LOW RISK** - Feature broken for 3 years with no incidents
+- If anything used jQuery UI, it would have broken in 2022
+- Modern Stimulus/Turbo stack doesn't use jQuery UI patterns
+
+**Files requiring jquery-ui:**
+1. Gemfile (line 26): `gem 'jquery-ui-rails'`
+2. app/assets/javascripts/application.js (line 18): `//= require jquery-ui`
+3. app/assets/stylesheets/application.scss (line 18): `*= require jquery-ui`
+
+**Conclusion:** Safe to remove completely alongside rails4-autocomplete.
+
+## Conclusion
+
+The rails4-autocomplete feature was:
+1. Added in September 2015 and worked correctly
+2. Accidentally broken in April 2022 during Bootstrap 5 migration
+3. Remained broken for nearly 3 years without user reports
+4. Depends on a 12-year-old unmaintained gem
+5. Represents pure technical debt with no active functionality
+
+The jquery-ui-rails dependency was:
+1. Added specifically for rails4-autocomplete (same commit)
+2. Never used for any other purpose
+3. Safe to remove with minimal risk
+
+**Recommendation:** Proceed with complete removal of both gems as outlined in Option 1.