diff --git a/lib/inferno/apps/cli/execute.rb b/lib/inferno/apps/cli/execute.rb
index a57049b59..3a03d10e8 100644
--- a/lib/inferno/apps/cli/execute.rb
+++ b/lib/inferno/apps/cli/execute.rb
@@ -1,9 +1,8 @@
-require 'pastel'
 require 'active_support'
 require_relative '../../utils/verify_runnable'
 require_relative '../../utils/persist_inputs'
-require_relative 'execute/console_outputter'
-require_relative '../../result_summarizer'
+
+Dir[File.join(__dir__, 'execute', '*_outputter.rb')].each { |outputter| require outputter }
 
 module Inferno
   module CLI
@@ -11,6 +10,13 @@ class Execute
       include ::Inferno::Utils::VerifyRunnable
       include ::Inferno::Utils::PersistInputs
 
+      OUTPUTTERS = {
+        'console' => Inferno::CLI::Execute::ConsoleOutputter,
+        'plain' => Inferno::CLI::Execute::PlainOutputter,
+        'json' => Inferno::CLI::Execute::JSONOutputter,
+        'quiet' => Inferno::CLI::Execute::QuietOutputter
+      }.freeze
+
       attr_accessor :options
 
       def self.suppress_output
@@ -88,8 +94,12 @@ def print_help_and_exit
       end
 
       def outputter
-        # TODO: swap outputter based on options
-        @outputter ||= Inferno::CLI::Execute::ConsoleOutputter.new
+        unless OUTPUTTERS.key? options[:outputter]
+          raise StandardError,
+                "Unrecognized outputter #{options[:outputter]}"
+        end
+
+        @outputter ||= OUTPUTTERS[options[:outputter]].new
       end
 
       def all_selected_groups_and_tests
@@ -164,7 +174,6 @@ def create_params(test_session, runnable)
       end
 
       def dispatch_job(test_run)
-        # TODO: move suppression to outputter? better suppression?
         if options[:verbose]
           Jobs.perform(Jobs::ExecuteTestRun, test_run.id, force_synchronous: true)
         else
diff --git a/lib/inferno/apps/cli/execute/console_outputter.rb b/lib/inferno/apps/cli/execute/console_outputter.rb
index 66658579e..6235f1abb 100644
--- a/lib/inferno/apps/cli/execute/console_outputter.rb
+++ b/lib/inferno/apps/cli/execute/console_outputter.rb
@@ -1,16 +1,16 @@
 require 'pastel'
-require_relative '../../web/serializers/test_run'
-require_relative '../../web/serializers/result'
+require_relative 'serialize'
 
 module Inferno
   module CLI
     class Execute
       # @private
       class ConsoleOutputter
-        COLOR = Pastel.new
         CHECKMARK = "\u2713".freeze
         BAR = ('=' * 80).freeze
 
+        include Serialize
+
         def print_start_message(options)
           puts ''
           puts BAR
@@ -23,7 +23,6 @@ def print_start_message(options)
 
         def print_around_run(_options)
           puts 'Running tests. This may take a while...'
-          # TODO: spinner/progress bar
           yield
         end
 
@@ -46,15 +45,18 @@ def print_results(options, results)
 
         def print_end_message(options); end
 
-        def print_error(options, exception)
-          puts COLOR.red "Error: #{exception.full_message}"
-          verbose_print(options, exception.backtrace&.join('\n'))
+        def print_error(_options, exception)
+          puts color.red "Error: #{exception.full_message}"
         end
 
         # private
 
         def verbose_print(options, *args)
-          print(COLOR.dim(*args)) if options[:verbose]
+          print(color.dim(*args)) if options[:verbose]
+        end
+
+        def color
+          @color ||= Pastel.new(enabled: $stdout.tty?)
         end
 
         def verbose_puts(options, *args)
@@ -106,21 +108,21 @@ def format_outputs(result)
         def format_result(result) # rubocop:disable Metrics/CyclomaticComplexity
           case result.result
           when 'pass'
-            COLOR.bold.green(CHECKMARK, ' pass')
+            color.bold.green(CHECKMARK, ' pass')
           when 'fail'
-            COLOR.bold.red 'X fail'
+            color.bold.red 'X fail'
           when 'skip'
-            COLOR.yellow '* skip'
+            color.yellow '* skip'
           when 'omit'
-            COLOR.blue '* omit'
+            color.blue '* omit'
           when 'error'
-            COLOR.magenta 'X error'
+            color.magenta 'X error'
           when 'wait'
-            COLOR.bold '. wait'
+            color.bold '. wait'
           when 'cancel'
-            COLOR.red 'X cancel'
+            color.red 'X cancel'
           when 'running'
-            COLOR.bold '- running'
+            color.bold '- running'
           else
             raise StandardError.new, "Unrecognized result #{result.result}"
           end
@@ -133,19 +135,6 @@ def verbose_print_json_results(options, results)
           verbose_puts(options, serialize(results))
           verbose_puts(options, BAR)
         end
-
-        def serialize(entity)
-          case entity.class.to_s
-          when 'Array'
-            JSON.pretty_generate(entity.map { |item| JSON.parse serialize(item) })
-          when lambda { |x|
-                 defined?(x.constantize) && defined?("Inferno::Web::Serializers::#{x.split('::').last}".constantize)
-               }
-            "Inferno::Web::Serializers::#{entity.class.to_s.split('::').last}".constantize.render(entity)
-          else
-            raise StandardError, "CLI does not know how to serialize #{entity.class}"
-          end
-        end
       end
     end
   end
diff --git a/lib/inferno/apps/cli/execute/json_outputter.rb b/lib/inferno/apps/cli/execute/json_outputter.rb
new file mode 100644
index 000000000..4691bd660
--- /dev/null
+++ b/lib/inferno/apps/cli/execute/json_outputter.rb
@@ -0,0 +1,28 @@
+require_relative 'serialize'
+
+module Inferno
+  module CLI
+    class Execute
+      # @private
+      class JSONOutputter
+        include Serialize
+
+        def print_start_message(_options); end
+
+        def print_around_run(_options, &)
+          yield
+        end
+
+        def print_results(_options, results)
+          puts serialize(results)
+        end
+
+        def print_end_message(_options); end
+
+        def print_error(_options, exception)
+          puts exception.to_json
+        end
+      end
+    end
+  end
+end
diff --git a/lib/inferno/apps/cli/execute/plain_outputter.rb b/lib/inferno/apps/cli/execute/plain_outputter.rb
new file mode 100644
index 000000000..eb0b2f94d
--- /dev/null
+++ b/lib/inferno/apps/cli/execute/plain_outputter.rb
@@ -0,0 +1,18 @@
+require_relative 'console_outputter'
+
+module Inferno
+  module CLI
+    class Execute
+      # @private
+      class PlainOutputter < ConsoleOutputter
+        def print_error(_options, exception)
+          puts "Error: #{exception.full_message(highlight: false)}"
+        end
+
+        def color
+          @color ||= Pastel.new(enabled: false)
+        end
+      end
+    end
+  end
+end
diff --git a/lib/inferno/apps/cli/execute/quiet_outputter.rb b/lib/inferno/apps/cli/execute/quiet_outputter.rb
new file mode 100644
index 000000000..a76f76ae5
--- /dev/null
+++ b/lib/inferno/apps/cli/execute/quiet_outputter.rb
@@ -0,0 +1,22 @@
+module Inferno
+  module CLI
+    class Execute
+      # @private
+      class QuietOutputter
+        def print_start_message(_options); end
+
+        def print_around_run(_options, &)
+          yield
+        end
+
+        def print_results(_options, _results); end
+
+        def print_end_message(_options); end
+
+        def print_error(options, exception)
+          puts "Error: #{exception.full_message}" if options[:verbose]
+        end
+      end
+    end
+  end
+end
diff --git a/lib/inferno/apps/cli/execute/serialize.rb b/lib/inferno/apps/cli/execute/serialize.rb
new file mode 100644
index 000000000..f843fb071
--- /dev/null
+++ b/lib/inferno/apps/cli/execute/serialize.rb
@@ -0,0 +1,21 @@
+require 'active_support'
+require_relative '../../web/serializers/test_run'
+require_relative '../../web/serializers/result'
+
+module Inferno
+  module CLI
+    class Execute
+      # @private
+      module Serialize
+        def serialize(entity)
+          case entity.class.to_s
+          when 'Array'
+            JSON.pretty_generate(entity.map { |item| JSON.parse serialize(item) })
+          else
+            Inferno::Web::Serializers.const_get(entity.class.to_s.demodulize).render(entity)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/inferno/apps/cli/main.rb b/lib/inferno/apps/cli/main.rb
index 1a08db1c4..5b926b28c 100644
--- a/lib/inferno/apps/cli/main.rb
+++ b/lib/inferno/apps/cli/main.rb
@@ -74,6 +74,10 @@ def version
 
         You can view suite ids with: `bundle exec inferno suites`
 
+        You can select an output format with the `--outputter` option. Current outputters
+        are console (default), plain, quiet, and json. JSON-formatted output will copy
+        Inferno's REST API: https://inferno-framework.github.io/inferno-core/api-docs/#/Result.
+
         Examples:
 
             (These examples only work from within the inferno_core directory).
@@ -88,6 +92,12 @@ def version
                                                   patient_id:1234321 \
                                          --tests 1.01 1.02`
             => Run specific tests from suite
+
+            `bundle exec inferno execute --suite dev_validator \
+                                         --inputs "url:https://hapi.fhir.org/baseR4" \
+                                                  patient_id:1234321 \
+                                         --outputter json`
+            => Outputs test results in JSON
       END_OF_HELP
       desc 'execute', 'Run Inferno tests in command line'
       long_desc EXECUTE_HELP, wrap: false
@@ -97,7 +107,7 @@ def version
              desc: 'Test suite id to run or to select groups and tests from',
              banner: 'id'
       option :suite_options,
-             aliases: ['-u'], # NOTE: -o will be for outputter
+             aliases: ['-u'],
              type: :hash,
              desc: 'Suite options'
       option :groups,
@@ -116,6 +126,10 @@ def version
              aliases: ['-i'],
              type: :hash,
              desc: 'Inputs (i.e: --inputs=foo:bar goo:baz)'
+      option :outputter,
+             aliases: ['-o'],
+             default: 'console',
+             desc: 'Select an outputter format: console | plain | json | quiet'
       option :verbose,
              aliases: ['-v'],
              type: :boolean,
diff --git a/spec/inferno/cli/execute/console_outputter_spec.rb b/spec/inferno/cli/execute/console_outputter_spec.rb
index b82d95b38..7fda528bc 100644
--- a/spec/inferno/cli/execute/console_outputter_spec.rb
+++ b/spec/inferno/cli/execute/console_outputter_spec.rb
@@ -1,20 +1,11 @@
 require_relative '../../../../lib/inferno/apps/cli/execute/console_outputter'
+require_relative 'outputter_spec'
 
 RSpec.describe Inferno::CLI::Execute::ConsoleOutputter do
   let(:instance) { described_class.new }
   let(:options) { { verbose: true } }
 
-  describe '#serialize' do
-    let(:test_results) { create_list(:result, 2) }
-
-    it 'handles an array of test results without raising exception' do
-      expect { instance.serialize(test_results) }.to_not raise_error(StandardError)
-    end
-
-    it 'returns valid JSON' do
-      expect { JSON.parse(instance.serialize(test_results)) }.to_not raise_error(StandardError)
-    end
-  end
+  include_examples 'outputter_spec', described_class
 
   describe '#verbose_print' do
     it 'outputs when verbose is true' do
diff --git a/spec/inferno/cli/execute/json_outputter_spec.rb b/spec/inferno/cli/execute/json_outputter_spec.rb
new file mode 100644
index 000000000..5b0127b1e
--- /dev/null
+++ b/spec/inferno/cli/execute/json_outputter_spec.rb
@@ -0,0 +1,6 @@
+require_relative '../../../../lib/inferno/apps/cli/execute/json_outputter'
+require_relative 'outputter_spec'
+
+RSpec.describe Inferno::CLI::Execute::JSONOutputter do
+  include_examples 'outputter_spec', described_class
+end
diff --git a/spec/inferno/cli/execute/outputter_spec.rb b/spec/inferno/cli/execute/outputter_spec.rb
new file mode 100644
index 000000000..25243b5cf
--- /dev/null
+++ b/spec/inferno/cli/execute/outputter_spec.rb
@@ -0,0 +1,33 @@
+RSpec.shared_examples 'outputter_spec' do |outputter_class|
+  it 'responds to print_start_message' do
+    expect(outputter_class.new).to respond_to(:print_start_message)
+  end
+
+  it 'responds to print_around_run' do
+    expect(outputter_class.new).to respond_to(:print_around_run)
+  end
+
+  it 'method print_around_run yields' do
+    expect do
+      expect { |b| outputter_class.new.print_around_run({}, &b) }.to yield_control
+    end.to output(/.?/).to_stdout_from_any_process # required to prevent output in rspec
+  end
+
+  it 'responds to print_results' do
+    expect(outputter_class.new).to respond_to(:print_results)
+  end
+
+  it 'responds to print_end_message' do
+    expect(outputter_class.new).to respond_to(:print_end_message)
+  end
+
+  it 'responds to print_error' do
+    expect(outputter_class.new).to respond_to(:print_error)
+  end
+
+  it 'returns an object whose print_error does not raise exception nor exit' do
+    expect do
+      expect { outputter_class.new.print_error({}, StandardError.new('my error')) }.to_not raise_error
+    end.to output(/.?/).to_stdout # required to prevent output in rspec
+  end
+end
diff --git a/spec/inferno/cli/execute/plain_outputter_spec.rb b/spec/inferno/cli/execute/plain_outputter_spec.rb
new file mode 100644
index 000000000..5384214af
--- /dev/null
+++ b/spec/inferno/cli/execute/plain_outputter_spec.rb
@@ -0,0 +1,20 @@
+require_relative '../../../../lib/inferno/apps/cli/execute/plain_outputter'
+require_relative 'outputter_spec'
+
+RSpec.describe Inferno::CLI::Execute::PlainOutputter do
+  let(:instance) { described_class.new }
+  let(:results) { create_list(:result, 2) }
+  let(:options) { { outputter: 'plain', verbose: true } }
+
+  include_examples 'outputter_spec', described_class
+
+  it 'never outputs a color code' do
+    expect do
+      instance.print_start_message(options)
+      instance.print_around_run(options) { ' ' }
+      instance.print_results(options, results)
+      instance.print_end_message(options)
+      # instance.print_error(options, StandardError.new('Mock Error'))
+    end.to_not output(/\033/).to_stdout
+  end
+end
diff --git a/spec/inferno/cli/execute/quiet_outputter_spec.rb b/spec/inferno/cli/execute/quiet_outputter_spec.rb
new file mode 100644
index 000000000..439688d7c
--- /dev/null
+++ b/spec/inferno/cli/execute/quiet_outputter_spec.rb
@@ -0,0 +1,26 @@
+require_relative '../../../../lib/inferno/apps/cli/execute/quiet_outputter'
+require_relative 'outputter_spec'
+
+RSpec.describe Inferno::CLI::Execute::QuietOutputter do
+  let(:instance) { described_class.new }
+  let(:results) { create_list(:result, 2) }
+
+  include_examples 'outputter_spec', described_class
+
+  it 'never outputs when verbose is false' do
+    options = { outputter: 'quiet', verbose: false }
+
+    expect do
+      instance.print_start_message(options)
+      instance.print_around_run(options) { ' ' }
+      instance.print_results(options, results)
+      instance.print_end_message(options)
+      instance.print_error(options, StandardError.new('Mock Error'))
+    end.to_not output(/./).to_stdout
+  end
+
+  it 'outputs error when verbose is true' do
+    options = { outputter: 'quiet', verbose: true }
+    expect { instance.print_error(options, StandardError.new('Mock Error')) }.to output.to_stdout
+  end
+end
diff --git a/spec/inferno/cli/execute/serialize_spec.rb b/spec/inferno/cli/execute/serialize_spec.rb
new file mode 100644
index 000000000..097bae132
--- /dev/null
+++ b/spec/inferno/cli/execute/serialize_spec.rb
@@ -0,0 +1,18 @@
+require_relative '../../../../lib/inferno/apps/cli/execute/serialize'
+
+RSpec.describe Inferno::CLI::Execute::Serialize do
+  let(:dummy_class) { Class.new { include Inferno::CLI::Execute::Serialize } }
+  let(:instance) { dummy_class.new }
+
+  describe '#serialize' do
+    let(:test_results) { create_list(:result, 2) }
+
+    it 'handles an array of test results without raising exception' do
+      expect { instance.serialize(test_results) }.to_not raise_error(StandardError)
+    end
+
+    it 'returns JSON' do
+      expect { JSON.parse(instance.serialize(test_results)) }.to_not raise_error(StandardError)
+    end
+  end
+end
diff --git a/spec/inferno/cli/execute_spec.rb b/spec/inferno/cli/execute_spec.rb
index 9460fd4da..37969ce64 100644
--- a/spec/inferno/cli/execute_spec.rb
+++ b/spec/inferno/cli/execute_spec.rb
@@ -26,37 +26,16 @@
   end
 
   describe '#outputter' do
-    it 'returns an object that responds to print_start_message' do
-      expect(instance.outputter).to respond_to(:print_start_message)
-    end
-
-    it 'returns an object that responds to print_around_run' do
-      expect(instance.outputter).to respond_to(:print_around_run)
-    end
-
-    it 'returns an object whose print_around_run yields' do
-      expect do
-        expect { |b| instance.outputter.print_around_run({}, &b) }.to yield_control
-      end.to output(/.?/).to_stdout # required to prevent output in rspec
-    end
-
-    it 'returns an object that responds to print_results' do
-      expect(instance.outputter).to respond_to(:print_results)
-    end
-
-    it 'returns an object that responds to print_end_message' do
-      expect(instance.outputter).to respond_to(:print_end_message)
-    end
-
-    it 'returns an object that responds to print_error' do
-      expect(instance.outputter).to respond_to(:print_error)
-    end
-
-    it 'returns an object whose print_error does not raise exception nor exit' do
-      allow(instance).to receive(:options).and_return({})
-      expect do
-        expect { instance.outputter.print_error({}, StandardError.new('my error')) }.to_not raise_error
-      end.to output(/.?/).to_stdout # required to prevent output in rspec
+    {
+      'console' => Inferno::CLI::Execute::ConsoleOutputter,
+      'plain' => Inferno::CLI::Execute::PlainOutputter,
+      'json' => Inferno::CLI::Execute::JSONOutputter,
+      'quiet' => Inferno::CLI::Execute::QuietOutputter
+    }.each do |selected_outputter, expected_class|
+      it "returns #{expected_class} given '#{selected_outputter}'" do
+        allow(instance).to receive(:options).and_return({ outputter: selected_outputter })
+        expect(instance.outputter).to be_an_instance_of expected_class
+      end
     end
   end
 
@@ -268,7 +247,7 @@
         .to_return(status: 200, body: FHIR::Patient.new({ name: { given: 'Smith' } }).to_json)
 
       expect do
-        expect { instance.run({ suite:, inputs:, verbose: true }) }
+        expect { instance.run({ suite:, inputs:, outputter: 'plain', verbose: true }) }
           .to raise_error(an_instance_of(SystemExit).and(having_attributes(status: 0)))
       end.to output(/.+/).to_stdout
     end