diff --git a/README.md b/README.md
index fa5bf53..841fdd7 100644
--- a/README.md
+++ b/README.md
@@ -20,16 +20,58 @@ Or install it yourself as:
     $ gem install nppes_api
 
 ## Usage
-
-The entrypoint for searches is at NPPESApi.search. See the code in lib/nppes_api.rb for information on the options that you can pass,
-which are the same as the ones [described by NPPES](https://npiregistry.cms.hhs.gov/api/demo). A successful search will return an
-NPPESApi::SearchResults object, from which you can call methods to retrieve data or call the raw_data method to get the original JSON.
+The entrypoint for searches is at NPPESApi.search. See the code in `lib/nppes_api.rb` for information on the options that you can pass, which are the same as the ones [described by NPPES](https://npiregistry.cms.hhs.gov/api-page). A successful search will return an
+`NPPESApi::SearchResults` object, from which you can call methods to retrieve data or call the `raw_data` method to get the original JSON.
 Here is an example query:
 
 ```
 NPPESApi.search(number: 1932494937).results.first.taxonomies.first.state #=> 'NC'
 ```
 
+## Search Results Methods and Objects
+A successful `NPPESApi.search()` call will return an `NPPESApi::SearchResults` object, which contains the following objects/methods:
+
+- `raw_data`: The raw JSON returned by the NPPES API, as a Hash
+- `result_count`: The number of results returned by the search
+- `results`: An array of `NPPESApi::Provider` objects, which have the following objects/methods:
+  - `created_epoch`
+  - `enumeration_type`
+  - `last_updated_epoch`
+  - `number`
+  - `other_names`
+  - `identifiers`
+  - `basic`: an `NPPESApi::Basic` object, which has the following objects/methods:
+    - `first_name`
+    - `last_name`
+    - `middle_name`
+    - `credential`
+    - `sole_proprietor`
+    - `gender`
+    - `enumeration_date`
+    - `last_updated`
+    - `status`
+    - `name_prefix`
+    - `name_suffix`
+  - `addresses`: An array of `NPPESApi::Address` objects, which have the following objects/methods:
+    - `country_code`
+    - `country_name`
+    - `address_purpose`
+    - `address_type`
+    - `address_1`
+    - `address_2`
+    - `city`
+    - `state`
+    - `postal_code`
+    - `telephone_number`
+    - `fax_number`
+  - `taxonomies`: An array of `NPPESApi::Taxonomy` objects, which have the following objects/methods:
+    - `state`
+    - `code`
+    - `primary`
+    - `license`
+    - `des`
+
+
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
diff --git a/lib/nppes_api.rb b/lib/nppes_api.rb
index 340b42e..3997fa8 100644
--- a/lib/nppes_api.rb
+++ b/lib/nppes_api.rb
@@ -38,6 +38,10 @@ module NPPESApi
   # @param limit [Integer] Limit results, default = 10, max = 200
   # @param skip [Integer] Skip first N results, max = 1000
   def self.search(options = {})
+    # Append the API version number to the options hash.
+    # Note that as of November 2022, the latest API version is 2.1, according to
+    # https://npiregistry.cms.hhs.gov/api-page
+    options[:version] = '2.1' # this version flag is required as of version 2.1
     SearchResults.new(RestClient.get('https://npiregistry.cms.hhs.gov/api', params: options).body)
   end
 end
diff --git a/lib/nppes_api/address.rb b/lib/nppes_api/address.rb
index d29016a..a94e1fe 100644
--- a/lib/nppes_api/address.rb
+++ b/lib/nppes_api/address.rb
@@ -5,16 +5,17 @@ def initialize(data)
     end
 
     methods = [
+      :country_code,
+      :country_name,
+      :address_purpose,
+      :address_type,
       :address_1,
       :address_2,
       :city,
       :state,
       :postal_code,
       :telephone_number,
-      :country_code,
-      :country_name,
-      :address_type,
-      :address_purpose
+      :fax_number
     ]
 
     methods.each do |meth|
diff --git a/lib/nppes_api/basic.rb b/lib/nppes_api/basic.rb
index e0b4f22..6c3ec0b 100644
--- a/lib/nppes_api/basic.rb
+++ b/lib/nppes_api/basic.rb
@@ -5,16 +5,25 @@ def initialize(data)
     end
 
     methods = [
-      :status,
-      :credential,
       :first_name,
       :last_name,
       :middle_name,
-      :name,
-      :gender,
+      :credential,
       :sole_proprietor,
+      :gender,
+      :enumeration_date,
       :last_updated,
-      :enumeration_date
+      :status,
+      :name_prefix,
+      :name_suffix,
+      :authorized_official_first_name,
+      :authorized_official_last_name,
+      :authorized_official_middle_name,
+      :authorized_official_title_or_position,
+      :authorized_official_telephone_number,
+      :authorized_official_name_prefix,
+      :authorized_official_name_suffix,
+      :authorized_official_credential
     ]
 
     methods.each do |meth|
@@ -24,3 +33,5 @@ def initialize(data)
     end
   end
 end
+
+
diff --git a/lib/nppes_api/search_results.rb b/lib/nppes_api/search_results.rb
index 560f714..43510aa 100644
--- a/lib/nppes_api/search_results.rb
+++ b/lib/nppes_api/search_results.rb
@@ -15,7 +15,7 @@ def result_count
     end
 
     def results
-      @results ||= @data['results'].map { |i| Provider.new(i) }
+      @results ||= @data['results']&.map { |i| Provider.new(i) }
     end
   end
 end
diff --git a/lib/nppes_api/version.rb b/lib/nppes_api/version.rb
index caace6d..12af762 100644
--- a/lib/nppes_api/version.rb
+++ b/lib/nppes_api/version.rb
@@ -1,3 +1,3 @@
 module NPPESApi
-  VERSION = '0.1.1'.freeze
+  VERSION = '1.0.1'.freeze
 end
diff --git a/spec/nppes_api_spec.rb b/spec/nppes_api_spec.rb
index be8f66b..bf2b7c7 100644
--- a/spec/nppes_api_spec.rb
+++ b/spec/nppes_api_spec.rb
@@ -4,4 +4,10 @@
   it 'has a version number' do
     expect(NPPESApi::VERSION).not_to be nil
   end
+  it 'successfully searches for a provider' do
+    expect(NPPESApi.search(number: 1932494937).results.first.taxonomies.first.state).to eq('NC')
+  end
+  it 'gracefully handles a nil search' do
+    expect(NPPESApi.search(number: 00000000).results).to be_nil
+  end
 end