diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 00000000..a7379978
Binary files /dev/null and b/.DS_Store differ
diff --git a/lib/account.rb b/lib/account.rb
index e69de29b..cdc74bf9 100644
--- a/lib/account.rb
+++ b/lib/account.rb
@@ -0,0 +1,57 @@
+require 'CSV'
+module Bank
+  class Account
+    attr_reader :id, :balance, :date
+
+    def initialize(id, balance, date)
+      raise ArgumentError.new("balance must be >= 0") if balance < 0
+      @id = id.to_i
+      @balance = balance.to_i
+      @date = date
+    end
+
+    def withdraw(amount, fee = 0, min_balance = 0)
+      raise ArgumentError.new ("Nice try! You can't withdraw negative money, and withdrawing $0 would be a waste of our time.") if amount <= 0
+
+      balance_would_be = @balance - amount - fee
+
+      if balance_would_be < min_balance
+        puts "You don't have enough money to withdraw #{amount} cents."
+
+        puts "There would be a #{fee} convenience fees."
+
+        puts "You must maintain a minimum balance of #{min_balance} cents."
+      else
+        @balance = balance_would_be
+      end
+      return @balance
+    end
+
+    def deposit(amount)
+      raise ArgumentError.new ("We don't want your debt (negative money)  here!") if amount < 0
+
+      @balance += amount
+      return @balance
+    end
+
+    # returns a collection of Account instances, representing all of the Accounts described in CSV
+    def self.all(csv_filename)
+      CSV.read(csv_filename).map do |row|
+        id = row[0].to_i
+        balance = row[1].to_i
+        date = row[2]
+        self.new(id, balance, date)
+      end
+      #return accounts
+    end
+
+    def self.find(csv_filename, id_to_find)
+      fail = proc {
+        raise ArgumentError.new("There is no client with the id you entered.")
+      }
+      self.all(csv_filename).find(fail) do |acct|
+        acct.id.to_i == id_to_find.to_i
+      end
+    end
+  end
+end
diff --git a/lib/checking_account.rb b/lib/checking_account.rb
new file mode 100644
index 00000000..7f907729
--- /dev/null
+++ b/lib/checking_account.rb
@@ -0,0 +1,32 @@
+module Bank
+  class CheckingAccount < Account
+    def initialize(id, balance, date)
+      super(id, balance, date)
+      @withdrawals_by_check = 0
+    end
+
+    def withdraw(amount, fee = 100, min_balance = 0)
+      super(amount, fee, min_balance)
+      return @balance
+    end
+
+    def withdraw_using_check(amount)
+      balance_before_withdrawal = @balance
+
+      if @withdrawals_by_check > 2
+        self.withdraw(amount, fee = 200, min_balance = -1000 )
+      else
+        self.withdraw(amount, fee = 0, min_balance = -1000 )
+      end
+
+      if @balance < balance_before_withdrawal
+        @withdrawals_by_check += 1
+      end
+      @balance =  balance
+    end
+
+    def reset_checks
+      @withdrawals_by_check = 0
+    end
+  end
+end
diff --git a/lib/savings_account.rb b/lib/savings_account.rb
new file mode 100644
index 00000000..c18b349d
--- /dev/null
+++ b/lib/savings_account.rb
@@ -0,0 +1,25 @@
+
+module Bank
+  class SavingsAccount < Account
+    def initialize(id, balance, date)
+
+      raise ArgumentError.new("balance must be at least $10") if balance < 1000
+
+      super(id, balance, date)
+    end
+
+    def withdraw(amount)
+      fee = 200
+      min_balance = 1000
+      super(amount, fee, min_balance)
+    end
+
+    def add_interest(rate)
+      raise ArgumentError.new("Negative interest rates are not only bad for your finances; they are illegal") if rate < 0
+
+      interest = @balance * rate/100
+      @balance += interest
+      return interest
+    end
+  end
+end
diff --git a/specs/account_spec.rb b/specs/account_spec.rb
index 6c399139..1cfaf6ec 100644
--- a/specs/account_spec.rb
+++ b/specs/account_spec.rb
@@ -2,8 +2,10 @@
 require 'minitest/reporters'
 require 'minitest/skip_dsl'
 require_relative '../lib/account'
+require 'CSV'
+require 'skip'
 
-describe "Wave 1" do
+xdescribe "Wave 1" do
   describe "Account#initialize" do
     it "Takes an ID and an initial balance" do
       id = 1337
@@ -17,6 +19,7 @@
       account.balance.must_equal balance
     end
 
+
     it "Raises an ArgumentError when created with a negative balance" do
       # Note: we haven't talked about procs yet. You can think
       # of them like blocks that sit by themselves.
@@ -27,6 +30,7 @@
       }.must_raise ArgumentError
     end
 
+
     it "Can be created with a balance of 0" do
       # If this raises, the test will fail. No 'must's needed!
       Bank::Account.new(1337, 0)
@@ -56,11 +60,12 @@
       updated_balance.must_equal expected_balance
     end
 
+
+
     it "Outputs a warning if the account would go negative" do
       start_balance = 100.0
       withdrawal_amount = 200.0
-      account = Bank::Account.new(1337, start_balance)
-
+      account = Bank::Account.new(1337, start_balance,)
       # Another proc! This test expects something to be printed
       # to the terminal, using 'must_output'. /.+/ is a regular
       # expression matching one or more characters - as long as
@@ -101,6 +106,7 @@
     end
   end
 
+
   describe "Account#deposit" do
     it "Increases the balance" do
       start_balance = 100.0
@@ -136,36 +142,90 @@
   end
 end
 
+
 # TODO: change 'xdescribe' to 'describe' to run these tests
-xdescribe "Wave 2" do
+describe "Wave 2" do
   describe "Account.all" do
-    it "Returns an array of all accounts" do
-      # TODO: Your test code here!
-      # Useful checks might include:
-      #   - Account.all returns an array
-      #   - Everything in the array is an Account
-      #   - The number of accounts is correct
-      #   - The ID and balance of the first and last
-      #       accounts match what's in the CSV file
-      # Feel free to split this into multiple tests if needed
+
+    #   - Account.all returns an array
+    it "Returns an array" do
+      accounts = Bank::Account.all("support/accounts.csv")
+      accounts.must_be_kind_of (Array)
+    end
+
+    it "contains only accounts" do
+      accounts = Bank::Account.all("support/accounts.csv")
+      accounts.each do |acct|
+        acct.must_be_kind_of Bank::Account
+      end
+    end
+
+    it "has the right number of elements" do
+      accounts = Bank::Account.all("support/accounts.csv")
+
+      accounts.length == CSV.read("support/accounts.csv").length
+    end
+
+    it "matches the first and last row" do
+      accounts = Bank::Account.all("support/accounts.csv")
+      compare_to = CSV.read("support/accounts.csv")
+
+      accounts.first.id.must_equal compare_to.first.first.to_i
+
+      accounts.first.balance.must_equal compare_to.first[1].to_i
+
+      accounts.last.balance.must_equal compare_to.last[1].to_i
+
+      accounts.last.balance.must_equal compare_to.last[1].to_i
     end
   end
 
+
   describe "Account.find" do
     it "Returns an account that exists" do
-      # TODO: Your test code here!
+      csv_filename = "support/accounts.csv"
+
+      account = Bank::Account.find(csv_filename, 1212)
+
+      acct_arr  =  [account.id.to_s, account.balance.to_s, account.date]
+
+      exists = false
+      CSV.open(csv_filename).each do |row|
+        if acct_arr == row
+          exists = true
+        end
+      end
+      exists.must_equal true
     end
 
+
     it "Can find the first account from the CSV" do
-      # TODO: Your test code here!
+      csv_filename = "support/accounts.csv"
+      first_row = CSV.read(csv_filename).first
+
+      account = Bank::Account.find(csv_filename, first_row.first)
+
+      acct_arr  =  [account.id.to_s, account.balance.to_s, account.date]
+
+      acct_arr.must_equal first_row
+
     end
 
     it "Can find the last account from the CSV" do
-      # TODO: Your test code here!
+      csv_filename = "support/accounts.csv"
+      last_row = CSV.read(csv_filename).last
+
+      account = Bank::Account.find(csv_filename, last_row.first)
+
+      acct_arr  =  [account.id.to_s, account.balance.to_s, account.date]
+
+      acct_arr.must_equal last_row
     end
 
     it "Raises an error for an account that doesn't exist" do
-      # TODO: Your test code here!
+      proc {
+        Bank::Account.find("support/accounts.csv", "5892")
+      }.must_raise ArgumentError
     end
   end
 end
diff --git a/specs/checking_account_spec.rb b/specs/checking_account_spec.rb
index 7f95339e..c6d71348 100644
--- a/specs/checking_account_spec.rb
+++ b/specs/checking_account_spec.rb
@@ -1,80 +1,215 @@
 require 'minitest/autorun'
 require 'minitest/reporters'
 require 'minitest/skip_dsl'
+require_relative '../lib/checking_account'
+
 
-# TODO: uncomment the next line once you start wave 3 and add lib/checking_account.rb
-# require_relative '../lib/checking_account'
 
 # Because a CheckingAccount is a kind
 # of Account, and we've already tested a bunch of functionality
 # on Account, we effectively get all that testing for free!
 # Here we'll only test things that are different.
 
-# TODO: change 'xdescribe' to 'describe' to run these tests
-xdescribe "CheckingAccount" do
+describe "CheckingAccount" do
   describe "#initialize" do
     # Check that a CheckingAccount is in fact a kind of account
     it "Is a kind of Account" do
-      account = Bank::CheckingAccount.new(12345, 100.0)
+      account = Bank::CheckingAccount.new(12345, 100.0,"NA")
       account.must_be_kind_of Bank::Account
     end
   end
 
   describe "#withdraw" do
     it "Applies a $1 fee each time" do
-      # TODO: Your test code here!
-    end
+      start_balance = 1399
+      withdrawal_amount = 100
+      account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+
+      updated_balance = account.withdraw(withdrawal_amount)
 
-    it "Doesn't modify the balance if the fee would put it negative" do
-      # TODO: Your test code here!
+      # Both the value returned and the balance in the account
+      # must be un-modified.
+      updated_balance.must_equal (start_balance - 100 - withdrawal_amount)
+      account.balance.must_equal (start_balance - 100-withdrawal_amount)
     end
   end
 
-  describe "#withdraw_using_check" do
-    it "Reduces the balance" do
-      # TODO: Your test code here!
-    end
+  it "Doesn't modify the balance if the fee would put it negative" do
+    start_balance = 1399
+    withdrawal_amount = 1300
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
 
-    it "Returns the modified balance" do
-      # TODO: Your test code here!
-    end
+    updated_balance = account.withdraw(withdrawal_amount)
 
-    it "Allows the balance to go down to -$10" do
-      # TODO: Your test code here!
-    end
+    # Both the value returned and the balance in the account
+    # must be un-modified.
+    updated_balance.must_equal start_balance
+    account.balance.must_equal start_balance
 
-    it "Outputs a warning if the account would go below -$10" do
-      # TODO: Your test code here!
-    end
+  end
+end
 
-    it "Doesn't modify the balance if the account would go below -$10" do
-      # TODO: Your test code here!
-    end
+describe "#withdraw_using_check" do
+  it "Reduces the balance" do
+    start_balance = 1399
+    withdrawal_amount = 1300
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
 
-    it "Requires a positive withdrawal amount" do
-      # TODO: Your test code here!
-    end
+    updated_balance = account.withdraw_using_check(withdrawal_amount)
 
-    it "Allows 3 free uses" do
-      # TODO: Your test code here!
-    end
+    # Both the value returned and the balance in the account
+    # must be un-modified.
+    (updated_balance - start_balance).wont_equal
+    ((updated_balance - start_balance).abs)
+  end
+
+  it "Returns the modified balance" do
+    start_balance = 1400
+    withdrawal_amount = 1300
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+    updated_balance = account.withdraw_using_check(withdrawal_amount)
+
+    expected_balance = start_balance - withdrawal_amount
+
+    updated_balance.must_equal expected_balance #account.balance.must_equal expected_balance
 
-    it "Applies a $2 fee after the third use" do
-      # TODO: Your test code here!
-    end
   end
 
-  describe "#reset_checks" do
-    it "Can be called without error" do
-      # TODO: Your test code here!
-    end
+  it "Allows the balance to go down to -$10" do
+    start_balance = 1400
+    withdrawal_amount = 1410
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+    updated_balance = account.withdraw_using_check(withdrawal_amount)
 
-    it "Makes the next three checks free if less than 3 checks had been used" do
-      # TODO: Your test code here!
-    end
+    expected_balance = start_balance - withdrawal_amount
+
+    updated_balance.must_equal expected_balance #account.balance.must_equal expected_balance
+  end
+
+  it "Outputs a warning if the account would go below -$10" do
+    start_balance = 1000
+    withdrawal_amount = 3000
+    account = Bank::CheckingAccount.new(1337, start_balance,"BA")
+    # Another proc! This test expects something to be printed
+    # to the terminal, using 'must_output'. /.+/ is a regular
+    # expression matching one or more characters - as long as
+    # anything at all is printed out the test will pass.
+    proc {
+      account.withdraw_using_check(withdrawal_amount)
+    }.must_output /.+/
+  end
+
+  it "Doesn't modify the balance if the account would go below -$10" do
+    start_balance = 10000
+    withdrawal_amount = 20001
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+
+    updated_balance = account.withdraw_using_check(withdrawal_amount)
+
+    # Both the value returned and the balance in the account
+    # must be un-modified.
+    updated_balance.must_equal start_balance
+    account.balance.must_equal start_balance
+
+  end
+
+  it "Requires a positive withdrawal amount" do
+    start_balance = 10000
+    withdrawal_amount = 0
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+
+    proc {
+      account.withdraw_using_check(withdrawal_amount)
+    }.must_raise ArgumentError
+  end
+
+  it "Allows 3 free uses" do
+    start_balance = 10000
+    withdrawal_amount = 2000
+
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+
+
+    3.times {account.withdraw_using_check(withdrawal_amount)}
+    updated_balance = account.balance
+
+    expected_balance = start_balance - 3 * withdrawal_amount
+
+    updated_balance.must_equal expected_balance
+  end
+
+  it "Applies a $2 fee after the third use" do
+    start_balance = 10000
+    withdrawal_amount = 2000
+
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+
+
+    4.times {account.withdraw_using_check(withdrawal_amount)}
+    updated_balance = account.balance
+
+    expected_balance = start_balance - 4 * withdrawal_amount - 200
+
+    updated_balance.must_equal expected_balance
+  end
+end
+
+describe "#reset_checks" do
+  it "Can be called without error" do
+    start_balance = 1000000
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+    account.reset_checks
+  end
+
+  it "Makes the next three checks free if less than 3 checks had been used" do
+
+    start_balance = 10000
+    withdrawal_amount = 100
+
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+
+
+    2.times {account.withdraw_using_check(withdrawal_amount)}
+
+    expected_balance = start_balance - 2 * withdrawal_amount
+
+    account.reset_checks
+
+
+    3.times {account.withdraw_using_check(withdrawal_amount)}
+
+    expected_balance = expected_balance - 3 * withdrawal_amount
+
+    updated_balance = account.balance
+
+
+    updated_balance.must_equal expected_balance
+
+
+  end
+
+  it "Makes the next three checks free if more than 3 checks had been used" do
+    start_balance = 10000
+    withdrawal_amount = 100
+
+    account = Bank::CheckingAccount.new(1337, start_balance, "NA")
+
+
+    4.times {account.withdraw_using_check(withdrawal_amount)}
+
+    expected_balance = start_balance - 4 * withdrawal_amount - 200
+
+    account.reset_checks
+
+
+    3.times {account.withdraw_using_check(withdrawal_amount)}
+
+    expected_balance = expected_balance - 3 * withdrawal_amount
+
+    updated_balance = account.balance
+
+
+    updated_balance.must_equal expected_balance
 
-    it "Makes the next three checks free if more than 3 checks had been used" do
-      # TODO: Your test code here!
-    end
   end
 end
diff --git a/specs/savings_account_spec.rb b/specs/savings_account_spec.rb
index 3f4d1e4a..af6c520d 100644
--- a/specs/savings_account_spec.rb
+++ b/specs/savings_account_spec.rb
@@ -1,58 +1,108 @@
 require 'minitest/autorun'
 require 'minitest/reporters'
 require 'minitest/skip_dsl'
+require_relative '../lib/savings_account'
 
-# TODO: uncomment the next line once you start wave 3 and add lib/savings_account.rb
-# require_relative '../lib/savings_account'
-
-# Because a SavingsAccount is a kind
-# of Account, and we've already tested a bunch of functionality
-# on Account, we effectively get all that testing for free!
-# Here we'll only test things that are different.
-
-# TODO: change 'xdescribe' to 'describe' to run these tests
-xdescribe "SavingsAccount" do
+describe "SavingsAccount" do
   describe "#initialize" do
     it "Is a kind of Account" do
       # Check that a SavingsAccount is in fact a kind of account
-      account = Bank::SavingsAccount.new(12345, 100.0)
+      account = Bank::SavingsAccount.new(12345, 50000,0)
       account.must_be_kind_of Bank::Account
     end
 
     it "Requires an initial balance of at least $10" do
       # TODO: Your test code here!
+      proc {
+        Bank::SavingsAccount.new(1337, 500, "NA")
+      }.must_raise ArgumentError
     end
   end
 
   describe "#withdraw" do
     it "Applies a $2 fee each time" do
-      # TODO: Your test code here!
-    end
+      start_balance = 12000
+      withdrawal_amount = 1800
+      account = Bank::SavingsAccount.new(1337, start_balance, "NA")
 
-    it "Outputs a warning if the balance would go below $10" do
-      # TODO: Your test code here!
-    end
+      account.withdraw(withdrawal_amount)
 
-    it "Doesn't modify the balance if it would go below $10" do
-      # TODO: Your test code here!
+      expected_balance = start_balance - withdrawal_amount - 200
+      account.balance.must_equal expected_balance
     end
+  end
 
-    it "Doesn't modify the balance if the fee would put it below $10" do
-      # TODO: Your test code here!
-    end
+
+  it "Outputs a warning if the balance would go below $10" do
+    start_balance = 1000
+    withdrawal_amount = 200
+    account = Bank::SavingsAccount.new(1337, start_balance,"NA")
+    # Another proc! This test expects something to be printed
+    # to the terminal, using 'must_output'. /.+/ is a regular
+    # expression matching one or more characters - as long as
+    # anything at all is printed out the test will pass.
+    proc {
+      account.withdraw(withdrawal_amount)
+    }.must_output /.+/
+  end
+
+  it "Doesn't modify the balance if it would go below $10" do
+    start_balance = 1000
+    withdrawal_amount = 200.0
+    account = Bank::SavingsAccount.new(1337, start_balance, "NA")
+
+    updated_balance = account.withdraw(withdrawal_amount)
+
+    # Both the value returned and the balance in the account
+    # must be un-modified.
+    updated_balance.must_equal start_balance
+    account.balance.must_equal start_balance
+  end
+
+  it "Doesn't modify the balance if the fee would put it below $10" do
+    start_balance = 1399
+    withdrawal_amount = 200
+    account = Bank::SavingsAccount.new(1337, start_balance, "NA")
+
+    updated_balance = account.withdraw(withdrawal_amount)
+
+    # Both the value returned and the balance in the account
+    # must be un-modified.
+    updated_balance.must_equal start_balance
+    account.balance.must_equal start_balance
   end
 
   describe "#add_interest" do
     it "Returns the interest calculated" do
-      # TODO: Your test code here!
+      start_amount = 10000
+      account = Bank::SavingsAccount.new(1337, start_amount, "NA")
+      rate = 0.25
+      expected_interest = start_amount * rate/100
+      account.add_interest(rate).must_equal expected_interest
     end
 
     it "Updates the balance with calculated interest" do
-      # TODO: Your test code here!
+      start_amount = 10000
+      account = Bank::SavingsAccount.new(1337, start_amount, "NA")
+      rate = 0.25
+
+      expected_balance = start_amount * (1 + rate/100)
+
+      account.add_interest(rate)
+      account.balance.must_equal expected_balance
     end
 
     it "Requires a positive rate" do
-      # TODO: Your test code here!
+      start_balance = 1000
+      rate = -0.25
+      account = Bank::SavingsAccount.new(1337, start_balance,"NA")
+      # Another proc! This test expects something to be printed
+      # to the terminal, using 'must_output'. /.+/ is a regular
+      # expression matching one or more characters - as long as
+      # anything at all is printed out the test will pass.
+      proc {
+        account.add_interest(rate)
+      }.must_raise ArgumentError
     end
   end
 end