diff --git a/app/services/pii/cacher.rb b/app/services/pii/cacher.rb
index d414197bf4a..27870abb8c5 100644
--- a/app/services/pii/cacher.rb
+++ b/app/services/pii/cacher.rb
@@ -13,17 +13,26 @@ def initialize(user, user_session)
 
     def save(user_password, profile = user.active_profile)
       decrypted_pii = profile.decrypt_pii(user_password) if profile
-      save_decrypted_pii(decrypted_pii) if decrypted_pii
+      save_decrypted_pii(decrypted_pii, profile.id) if decrypted_pii
       rotate_fingerprints(profile) if stale_fingerprints?(profile)
       user_session[:decrypted_pii]
     end
 
-    def save_decrypted_pii(decrypted_pii)
+    def save_decrypted_pii(decrypted_pii, profile_id = nil)
       user_session[:decrypted_pii] = decrypted_pii.to_json
+
+      if profile_id.present? && IdentityConfig.store.session_encrypted_profiles_write_enabled
+        Pii::ProfileCacher.new(user, user_session).save_decrypted_pii(decrypted_pii, profile_id)
+      end
+
       nil
     end
 
-    def fetch
+    def fetch(profile_id = nil)
+      if profile_id.present? && IdentityConfig.store.session_encrypted_profiles_read_enabled
+        return Pii::ProfileCacher.new(user, user_session).fetch(profile_id)
+      end
+
       pii_string = fetch_string
       return nil unless pii_string
 
@@ -37,6 +46,7 @@ def exists_in_session?
     def delete
       user_session.delete(:decrypted_pii)
       user_session.delete(:encrypted_pii)
+      Pii::ProfileCacher.new(user, user_session).delete
     end
 
     private
diff --git a/app/services/pii/profile_cacher.rb b/app/services/pii/profile_cacher.rb
new file mode 100644
index 00000000000..def7b7cc2e9
--- /dev/null
+++ b/app/services/pii/profile_cacher.rb
@@ -0,0 +1,69 @@
+module Pii
+  class ProfileCacher
+    attr_reader :user, :user_session
+
+    def initialize(user, user_session)
+      @user = user
+      @user_session = user_session
+    end
+
+    def save(user_password, profile = user.active_profile)
+      decrypted_pii = profile.decrypt_pii(user_password) if profile
+      save_decrypted_pii(decrypted_pii, profile.id) if decrypted_pii
+      rotate_fingerprints(profile, decrypted_pii) if stale_fingerprints?(profile, decrypted_pii)
+      decrypted_pii
+    end
+
+    def save_decrypted_pii(decrypted_pii, profile_id)
+      kms_encrypted_pii = SessionEncryptor.new.kms_encrypt(decrypted_pii.to_json)
+
+      user_session[:encrypted_profiles] ||= {}
+      user_session[:encrypted_profiles][profile_id.to_s] = kms_encrypted_pii
+    end
+
+    def fetch(profile_id)
+      return unless user_session[:encrypted_profiles].present?
+
+      encrypted_profile_pii = user_session[:encrypted_profiles][profile_id.to_s]
+      return unless encrypted_profile_pii.present?
+
+      decrypted_profile_pii_json = SessionEncryptor.new.kms_decrypt(encrypted_profile_pii)
+      Pii::Attributes.new_from_json(decrypted_profile_pii_json)
+    end
+
+    def exists_in_session?
+      user_session[:encrypted_profiles].present?
+    end
+
+    def delete
+      user_session.delete(:encrypted_profiles)
+    end
+
+    private
+
+    def rotate_fingerprints(profile, pii)
+      KeyRotator::HmacFingerprinter.new.rotate(
+        user: user,
+        profile: profile,
+        pii_attributes: pii,
+      )
+    end
+
+    def stale_fingerprints?(profile, pii)
+      stale_ssn_signature?(profile, pii) ||
+        stale_compound_pii_signature?(profile, pii)
+    end
+
+    def stale_ssn_signature?(profile, pii)
+      return false unless profile.present? && pii.present?
+      Pii::Fingerprinter.stale?(pii.ssn, profile.ssn_signature)
+    end
+
+    def stale_compound_pii_signature?(profile, pii)
+      return false unless profile.present? && pii.present?
+      compound_pii = Profile.build_compound_pii(pii)
+      return false unless compound_pii
+      Pii::Fingerprinter.stale?(compound_pii, profile.name_zip_birth_year_signature)
+    end
+  end
+end
diff --git a/config/application.yml.default b/config/application.yml.default
index c5b4ac666ca..b8a1229e1ef 100644
--- a/config/application.yml.default
+++ b/config/application.yml.default
@@ -298,6 +298,8 @@ seed_agreements_data: true
 service_provider_request_ttl_hours: 24
 session_check_delay: 30
 session_check_frequency: 30
+session_encrypted_profiles_read_enabled: true
+session_encrypted_profiles_write_enabled: true
 session_encryptor_alert_enabled: false
 session_timeout_in_minutes: 15
 session_timeout_warning_seconds: 150
@@ -478,6 +480,8 @@ production:
   scrypt_cost: 10000$8$1$
   secret_key_base:
   seed_agreements_data: false
+  session_encrypted_profiles_read_enabled: false
+  session_encrypted_profiles_write_enabled: false
   session_encryption_key:
   skip_encryption_allowed_list: '["urn:gov:gsa:SAML:2.0.profiles:sp:sso:dev", "urn:gov:gsa:SAML:2.0.profiles:sp:sso:int"]'
   state_tracking_enabled: false
diff --git a/lib/identity_config.rb b/lib/identity_config.rb
index 2b46412557a..ce7339d6abb 100644
--- a/lib/identity_config.rb
+++ b/lib/identity_config.rb
@@ -426,6 +426,8 @@ def self.build_store(config_map)
     config.add(:ses_configuration_set_name, type: :string)
     config.add(:session_check_delay, type: :integer)
     config.add(:session_check_frequency, type: :integer)
+    config.add(:session_encrypted_profiles_read_enabled, type: :boolean)
+    config.add(:session_encrypted_profiles_write_enabled, type: :boolean)
     config.add(:session_encryption_key, type: :string)
     config.add(:session_encryptor_alert_enabled, type: :boolean)
     config.add(:session_timeout_in_minutes, type: :integer)
diff --git a/spec/services/pii/profile_cacher_spec.rb b/spec/services/pii/profile_cacher_spec.rb
new file mode 100644
index 00000000000..07cad278b77
--- /dev/null
+++ b/spec/services/pii/profile_cacher_spec.rb
@@ -0,0 +1,158 @@
+require 'rails_helper'
+
+RSpec.describe Pii::ProfileCacher do
+  let(:password) { 'salty peanuts are best' }
+  let(:user) { create(:user, :with_phone, password: password) }
+  let(:user_session) { {}.with_indifferent_access }
+
+  let(:active_pii) do
+    Pii::Attributes.new(
+      first_name: 'Test',
+      last_name: 'Testerson',
+      dob: '2023-01-01',
+      zipcode: '10000',
+      ssn: '123-45-6789',
+    )
+  end
+  let(:active_profile) do
+    profile = create(:profile, :active, :verified, user: user)
+    profile.encrypt_pii(active_pii, password)
+    profile
+  end
+
+  let(:pending_pii) do
+    Pii::Attributes.new(
+      first_name: 'Test2',
+      last_name: 'Testerson2',
+      dob: '2023-01-01',
+      zipcode: '10000',
+      ssn: '999-99-9999',
+    )
+  end
+  let(:pending_profile) do
+    profile = create(:profile, :verified, :verify_by_mail_pending, user: user)
+    profile.encrypt_pii(pending_pii, password)
+    profile
+  end
+
+  subject { described_class.new(user, user_session) }
+
+  describe '#save' do
+    it 'writes decrypted PII to user_session for multiple profiles' do
+      decrypted_active_pii = subject.save(password, active_profile)
+      decrypted_pending_pii = subject.save(password, pending_profile)
+
+      expect(decrypted_active_pii).to eq(active_pii)
+      expect(decrypted_pending_pii).to eq(pending_pii)
+
+      encrypted_active_session_pii = user_session[:encrypted_profiles][active_profile.id.to_s]
+      decrypted_active_session_pii = SessionEncryptor.new.kms_decrypt(encrypted_active_session_pii)
+      expect(decrypted_active_session_pii).to eq(active_pii.to_json)
+
+      encrypted_pending_session_pii = user_session[:encrypted_profiles][pending_profile.id.to_s]
+      decrypted_pending_session_pii = SessionEncryptor.new.kms_decrypt(
+        encrypted_pending_session_pii,
+      )
+      expect(decrypted_pending_session_pii).to eq(pending_pii.to_json)
+    end
+
+    it 'updates PII bundle fingerprints when keys are rotated' do
+      old_ssn_signature = active_profile.ssn_signature
+      old_compound_pii_fingerprint = active_profile.name_zip_birth_year_signature
+
+      rotate_all_keys
+
+      # Create a new user object to drop the memoized encrypted attributes
+      reloaded_user = User.find(user.id)
+
+      described_class.new(reloaded_user, user_session).save(password, active_profile)
+
+      active_profile.reload
+
+      expect(active_profile.ssn_signature).to_not eq(old_ssn_signature)
+      expect(active_profile.name_zip_birth_year_signature).to_not eq(old_compound_pii_fingerprint)
+    end
+
+    it 'does not attempt to rotate nil attributes' do
+      cacher = described_class.new(user, user_session)
+      rotate_all_keys
+
+      expect { cacher.save(password, nil) }.to_not raise_error
+    end
+
+    it 'does not raise an error if pii fingerprint is nil but attributes are present' do
+      # The name_zip_birth_year_signature column was added after users  had
+      # ecrypted PII. As a result, those users may have a profile with valid PII
+      # and a nil value here. Caching the PII into the session for those users
+      # should update the signature column without raising an error
+      active_profile.update!(name_zip_birth_year_signature: nil)
+
+      subject.save(password, active_profile)
+
+      expect(active_profile.reload.name_zip_birth_year_signature).to_not be_nil
+    end
+
+    it 'raises an encryption error for an incorrect password' do
+      expect do
+        subject.save('incorrect password', active_profile)
+      end.to raise_error(Encryption::EncryptionError)
+    end
+  end
+
+  describe '#fetch' do
+    it 'fetches decrypted PII from user_session' do
+      user_session[:encrypted_profiles] = {
+        '123' => SessionEncryptor.new.kms_encrypt(active_pii.to_json),
+        '456' => SessionEncryptor.new.kms_encrypt(pending_pii.to_json),
+      }
+
+      result = subject.fetch(123)
+
+      expect(result).to eq(active_pii)
+    end
+
+    it 'returns nil if the encrypted profiles are not present' do
+      result = subject.fetch(123)
+
+      expect(result).to eq(nil)
+    end
+
+    it 'returns nil a profile has not been decrypted and loaded into the session' do
+      user_session[:encrypted_profiles] = {
+        '456' => SessionEncryptor.new.kms_encrypt(pending_pii.to_json),
+      }
+
+      result = subject.fetch(123)
+
+      expect(result).to eq(nil)
+    end
+  end
+
+  describe '#exists_in_session?' do
+    it 'returns true if the encrypted profiles are in the session' do
+      user_session[:encrypted_profiles] = {
+        '123' => SessionEncryptor.new.kms_encrypt(active_pii.to_json),
+        '456' => SessionEncryptor.new.kms_encrypt(pending_pii.to_json),
+      }
+
+      expect(subject.exists_in_session?).to eq(true)
+    end
+
+    it 'returns false if the encrypted profiles are in the session' do
+      expect(subject.exists_in_session?).to eq(false)
+    end
+  end
+
+  describe '#delete' do
+    it 'deletes the encrypted profiles from the session' do
+      user_session[:encrypted_profiles] = {
+        '123' => SessionEncryptor.new.kms_encrypt(active_pii.to_json),
+        '456' => SessionEncryptor.new.kms_encrypt(pending_pii.to_json),
+      }
+
+      subject.delete
+
+      expect(user_session).to eq({})
+    end
+  end
+end