diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 994e9db7..b5e188c1 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -148,27 +148,41 @@ Take a look at the `/variables/acts/social_security/residency.py` and considered
 The variable `social_security__residential_requirement` in this file that we will be referring to is supporting both the 1964 and the 2018 Social Security Acts.
 It's declaration looks like this:
 
-```
+```python
 class social_security__residential_requirement(variables.Variable):
     value_type = bool
     entity = entities.Person
     label = "Residential requirements for certain benefits, calculates for the 1964 and the 2018 Social Security Acts"
     definition_period = periods.MONTH
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783138", "https://www.legislation.govt.nz/act/public/1964/0136/latest/whole.html#DLM363796"
+    reference = [
+        "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783138",  # 2018-11-26
+        "https://www.legislation.govt.nz/act/public/1964/0136/latest/whole.html#DLM363796",  # 1964-12-04
+        ]
 ```
 - Note the two references (2018 and 1964). They link to the specific section of the act on legislation.govt.nz
 - Note the descriptive label
 - Note the naming convention as described in [Naming Variables](#namingvariables)
 
 The variable has two formulas:
-```
+```python
     def formula_1964_12_04(persons, period, parameters):
 ```
-```
+```python
     def formula_2018_11_26(persons, period, parameters):
 ```
 This is an OpenFisca feature that ensures the correct formula will be automatically applied depending on the date supplied with the scenario.
 
+To aid review, the reference list can contain links to the specific versions of legislation in effect for each formula.
+
+e.g.:
+
+```python
+    reference = [
+        "https://www.legislation.govt.nz/act/public/2018/0032/77.0/whole.html#DLM6783138",  # 2018-11-26
+        "https://www.legislation.govt.nz/act/public/2018/0032/140.0/whole.html#DLM6783138",  # 2020-11-09
+        ]
+```
+
 What is unique to this project is how we intend to code the content of these formulas.
 
 _At the time of writing variables within this project ARE NOT coded this way save for the example we will refer to below._
@@ -179,7 +193,7 @@ The first thing to recognise is it references the `section 16` of the Social Sec
 
 We choose to structure the code accordingly. This looks like this:
 
-```
+```python
 # ssa16_1 - Descriptive, not requiring coding.
 
 ssa16_2_a = persons("immigration__citizen_or_resident", period) * \
@@ -220,7 +234,8 @@ This allows us to map the extent and reach of the project. The `structure.json`
 ### structure.json
 
 An array of entries, one for each prefix utilised in the code base. In the format as follows:
-```
+
+```json
 {
     "Title": "Accident Compensation Act 2001",
     "Prefix": "acc",
@@ -233,6 +248,7 @@ An array of entries, one for each prefix utilised in the code base. In the forma
     ]
 }
 ```
+
 Title, Prefix, Type and Reference are all required.
  - Title: The legal title of the legal artifact
  - Prefix: The prefix utilised within the openfisca_aotearoa code base
@@ -279,8 +295,7 @@ This project currently utilises one specific pattern however for benefit calcula
 - `jobseeker_support__benefit` (float)
 
 i.e. the formula for `jobseeker_support__benefit` would be:
- ```
+
+ ```python
  jobseeker_support__entitled * min(jobseeker_support__base - jobseeker_support__reduction, jobseeker_support__cutoff)
  ```
-
-
diff --git a/openfisca_aotearoa/parameters/social_security/supported_living_payment/base.yaml b/openfisca_aotearoa/parameters/social_security/supported_living_payment/base.yaml
index 5220d76e..57e0b2dc 100644
--- a/openfisca_aotearoa/parameters/social_security/supported_living_payment/base.yaml
+++ b/openfisca_aotearoa/parameters/social_security/supported_living_payment/base.yaml
@@ -624,6 +624,14 @@ clauses:
           reference:
             title: Part 3 -> Schedule 4, Part 3, Clause 1(h)(ii)
             href: https://www.legislation.govt.nz/regulation/public/2024/0011/latest/whole.html
+  clause_1_income_disregarded:
+    values:
+      2018-11-26:
+        value: 20
+        metadata:
+          reference:
+            title: Part 3 -> Schedule 4, Part 3, Clause 1
+            href: https://www.legislation.govt.nz/act/public/2018/0032/59.0/DLM6784861.html
   clause_2:
     values:
       2018-11-26:
diff --git a/openfisca_aotearoa/tests/social_security/supported_living_payment/base.yaml b/openfisca_aotearoa/tests/social_security/supported_living_payment/base.yaml
index 99337b85..3721a7b6 100644
--- a/openfisca_aotearoa/tests/social_security/supported_living_payment/base.yaml
+++ b/openfisca_aotearoa/tests/social_security/supported_living_payment/base.yaml
@@ -826,7 +826,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__disabled_or_blind__entitled: true
+        supported_living_payment__disabled_or_blind: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 0
@@ -858,7 +858,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__disabled_or_blind__entitled: true
+        supported_living_payment__disabled_or_blind: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 0
@@ -890,7 +890,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__disabled_or_blind__entitled: true
+        supported_living_payment__disabled_or_blind: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 0
@@ -922,7 +922,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__disabled_or_blind__entitled: true
+        supported_living_payment__disabled_or_blind: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 0
@@ -954,7 +954,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__disabled_or_blind__entitled: true
+        supported_living_payment__disabled_or_blind: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 1
@@ -986,7 +986,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__disabled_or_blind__entitled: true
+        supported_living_payment__disabled_or_blind: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 1
@@ -1018,7 +1018,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__disabled_or_blind__entitled: true
+        supported_living_payment__disabled_or_blind: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 1
@@ -1050,7 +1050,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__disabled_or_blind__entitled: true
+        supported_living_payment__disabled_or_blind: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 1
@@ -1082,7 +1082,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__carer__entitled: true
+        supported_living_payment__carer: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 0
@@ -1114,7 +1114,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__carer__entitled: true
+        supported_living_payment__carer: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 0
@@ -1146,7 +1146,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__carer__entitled: true
+        supported_living_payment__carer: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 0
@@ -1178,7 +1178,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__carer__entitled: true
+        supported_living_payment__carer: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 0
@@ -1210,7 +1210,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__carer__entitled: true
+        supported_living_payment__carer: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 1
@@ -1242,7 +1242,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__carer__entitled: true
+        supported_living_payment__carer: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 1
@@ -1274,7 +1274,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__carer__entitled: true
+        supported_living_payment__carer: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 1
@@ -1306,7 +1306,7 @@
     persons:
       principal:
         supported_living_payment__entitled: true
-        supported_living_payment__carer__entitled: true
+        supported_living_payment__carer: true
         social_security__in_a_relationship: true
         age: 18
         social_security__dependent_children: 1
diff --git a/openfisca_aotearoa/variables/acts/social_security/schedule_4/part3.py b/openfisca_aotearoa/variables/acts/social_security/schedule_4/part3.py
index 1e23d0c3..d28833c7 100644
--- a/openfisca_aotearoa/variables/acts/social_security/schedule_4/part3.py
+++ b/openfisca_aotearoa/variables/acts/social_security/schedule_4/part3.py
@@ -10,8 +10,8 @@ class schedule_4__part3_1_a(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(a)"
+    reference = "https://legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(persons, period, parameters):
         single = numpy.logical_not(persons("social_security__in_a_relationship", period))
@@ -24,8 +24,8 @@ class schedule_4__part3_1_b(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(b)"
+    reference = "https://legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(persons, period, parameters):
         single = numpy.logical_not(persons("social_security__in_a_relationship", period))
@@ -38,8 +38,8 @@ class schedule_4__part3_1_c(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(c)"
+    reference = "https://legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(persons, period, parameters):
         single = numpy.logical_not(persons("social_security__in_a_relationship", period))
@@ -51,8 +51,8 @@ class schedule_4__part3_1_d(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(d)"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         in_relationship = people("social_security__in_a_relationship", period)
@@ -66,8 +66,8 @@ class schedule_4__part3_1_d_i(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(d)(i)"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_d", period)
@@ -79,8 +79,8 @@ class schedule_4__part3_1_d_ii(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(d)(ii)"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_d", period)
@@ -92,8 +92,11 @@ class schedule_4__part3_1_e(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(e)"
+    reference = [
+        "https://www.legislation.govt.nz/act/public/2018/0032/77.0/DLM6784861.html",  # 2018-11-26
+        "https://www.legislation.govt.nz/act/public/2018/0032/140.0/DLM6784861.html",  # 2020-11-09
+        ]
 
     def formula_2018_11_26(people, period, parameters):
         in_relationship = people("social_security__in_a_relationship", period)
@@ -117,8 +120,8 @@ class schedule_4__part3_1_e_i(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(e)(i)"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_e", period)
@@ -130,8 +133,8 @@ class schedule_4__part3_1_e_ii(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(e)(ii)"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_e", period)
@@ -144,9 +147,12 @@ class schedule_4__part3_1_f(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(f)"
     end = "2020-11-09"
+    reference = [
+        "https://www.legislation.govt.nz/act/public/2018/0032/77.0/DLM6784861.html",  # 2018-11-26
+        "https://www.legislation.govt.nz/act/public/2018/0032/140.0/DLM6784861.html",  # 2020-11-09  (removed)
+        ]
 
     def formula_2018_11_26(people, period, parameters):
         in_relationship = people("social_security__in_a_relationship", period)
@@ -160,9 +166,9 @@ class schedule_4__part3_1_f_i(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(f)(i)"
     end = "2020-11-09"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_f", period)
@@ -174,9 +180,9 @@ class schedule_4__part3_1_f_ii(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(f)(ii)"
     end = "2020-11-09"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_f", period)
@@ -188,11 +194,14 @@ class schedule_4__part3_1_g(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(g)"
+    reference = [
+        "https://www.legislation.govt.nz/act/public/2018/0032/77.0/DLM6784861.html",  # 2018-11-26
+        "https://www.legislation.govt.nz/act/public/2018/0032/140.0/DLM6784861.html",  # 2020-11-09
+        ]
 
     def formula_2018_11_26(people, period, parameters):
-        disabled_or_blind = people("supported_living_payment__disabled_or_blind__entitled", period)
+        disabled_or_blind = people("supported_living_payment__disabled_or_blind", period)
         in_relationship = people("social_security__in_a_relationship", period)
         partner_has_benefit = people.family.any(
             people.family.members("social_security__granted_main_benefit", period),
@@ -203,7 +212,7 @@ def formula_2018_11_26(people, period, parameters):
         return disabled_or_blind * in_relationship * numpy.logical_not(partner_has_benefit + partner_has_super)
 
     def formula_2020_11_09(people, period, parameters):
-        disabled_or_blind__entitled = people("supported_living_payment__disabled_or_blind__entitled", period)
+        disabled_or_blind__entitled = people("supported_living_payment__disabled_or_blind", period)
         in_relationship = people("social_security__in_a_relationship", period)
         partner_has_benefit = people.family.any(
             people.family.members("social_security__granted_main_benefit", period),
@@ -221,8 +230,8 @@ class schedule_4__part3_1_g_i(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(g)(i)"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_g", period)
@@ -234,8 +243,8 @@ class schedule_4__part3_1_g_ii(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(g)(ii)"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_g", period)
@@ -247,11 +256,14 @@ class schedule_4__part3_1_h(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(h)"
+    reference = [
+        "https://www.legislation.govt.nz/act/public/2018/0032/77.0/DLM6784861.html",  # 2018-11-26
+        "https://www.legislation.govt.nz/act/public/2018/0032/140.0/DLM6784861.html",  # 2020-11-09
+        ]
 
     def formula_2018_11_26(people, period, parameters):
-        carer__entitled = people("supported_living_payment__carer__entitled", period)
+        carer__entitled = people("supported_living_payment__carer", period)
         in_relationship = people("social_security__in_a_relationship", period)
         partner_has_benefit = people.family.any(
             people.family.members("social_security__granted_main_benefit", period),
@@ -262,7 +274,7 @@ def formula_2018_11_26(people, period, parameters):
         return carer__entitled * in_relationship * numpy.logical_not(partner_has_benefit + partner_has_super)
 
     def formula_2020_11_09(people, period, parameters):
-        carer__entitled = people("supported_living_payment__carer__entitled", period)
+        carer__entitled = people("supported_living_payment__carer", period)
         in_relationship = people("social_security__in_a_relationship", period)
         partner_has_benefit = people.family.any(
             people.family.members("social_security__granted_main_benefit", period),
@@ -280,8 +292,8 @@ class schedule_4__part3_1_h_i(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(h)(i)"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_h", period)
@@ -293,8 +305,8 @@ class schedule_4__part3_1_h_ii(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
     label = "Part 3 Supported Living Payment - Clause 1(g)(ii)"
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784861.html"
 
     def formula_2018_11_26(people, period, parameters):
         base = people("schedule_4__part3_1_h", period)
@@ -306,7 +318,7 @@ class schedule_4__part3_5(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    label = """Shortcut to indicate beneficiary meets the following from clause 5:
+    label = """Indicates beneficiary meets the following from clause 5:
         (a) has a psychiatric, intellectual, physical, or mental disability; and
         (b) is receiving long-term residential care in a hospital or rest home because of that disability; and
         (c) has not been means assessed under Part 6 of the Residential Care and Disability Support Services Act 2018.
@@ -318,7 +330,7 @@ class schedule_4__part3_6(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
-    label = """Shortcut to indicate beneficiary meets the following from clause 6:
+    label = """Indicates beneficiary meets the following from clause 6:
         if that spouse or partner is not receiving long-term residential care in a hospital or rest home.
     """
     reference = "https://legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6784861"
diff --git a/openfisca_aotearoa/variables/acts/social_security/supported_living_payment/supported_living_payment.py b/openfisca_aotearoa/variables/acts/social_security/supported_living_payment/supported_living_payment.py
index e3267f8f..ab4d5b86 100644
--- a/openfisca_aotearoa/variables/acts/social_security/supported_living_payment/supported_living_payment.py
+++ b/openfisca_aotearoa/variables/acts/social_security/supported_living_payment/supported_living_payment.py
@@ -12,20 +12,7 @@ class supported_living_payment__entitled(variables.Variable):
     definition_period = periods.WEEK
     set_input = holders.set_input_dispatch_by_period
     label = "Eligible for Supported Living Payment."
-    reference = [
-        "https://legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783175",
-        "http://legislation.govt.nz/act/public/1964/0136/latest/whole.html#DLM5468367",
-        ]
-
-    def formula_2013_07_15(persons, period, parameters):
-        """
-        For the 1964 version of the act (final version), this is split into two sections:
-            40B on ground of sickness, injury, disability, or total blindness
-            40D on ground of caring for patient requiring care
-        """
-        ssa40B = persons("supported_living_payment__disabled_or_blind__entitled", period, parameters)
-        ssa40D = persons("supported_living_payment__carer__entitled", period, parameters)
-        return ssa40B + ssa40D
+    reference = "https://legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783175"
 
     def formula_2018_11_26(persons, period, parameters):
         """
@@ -33,8 +20,8 @@ def formula_2018_11_26(persons, period, parameters):
             34 - 39 on ground of restricted work capacity or total blindness
             40 - 42 on ground of caring for another person
         """
-        ssa34 = persons("supported_living_payment__disabled_or_blind__entitled", period, parameters)
-        ssa40 = persons("supported_living_payment__carer__entitled", period, parameters)
+        ssa34 = persons("supported_living_payment__disabled_or_blind", period, parameters)
+        ssa40 = persons("supported_living_payment__carer", period, parameters)
 
         # ssa116 - must undergo work ability assessment
 
@@ -51,14 +38,12 @@ def formula_2018_11_26(persons, period, parameters):
         return ssa34 + ssa40
 
 
-class supported_living_payment__disabled_or_blind__entitled(variables.Variable):
+class supported_living_payment__disabled_or_blind(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
     label = "Eligible for Supported Living Payment, on ground of restricted work capacity or total blindness."
-    reference = [
-        "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783174",
-        ]
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783174"
 
     def formula_2018_11_26(persons, period, parameters):
         # person P has restricted work capacity or is totally blind
@@ -83,79 +68,13 @@ def formula_2018_11_26(persons, period, parameters):
 
         return ssa34_a * ssa34_b * ssa34_c * ssa36
 
-    def formula(persons, period, parameters):
-        # person P has restricted work capacity
-        ssa40B_1_a = persons("supported_living_payment__restricted_work_capacity", period.first_week)
-
-        # person P is totally blind
-        ssa40B_1_b = persons("totally_blind", period)
-
-        # person P is 16 or older
-        ssa40B_1A = persons("age", period.start) >= 16
-
-        # person P meets the residential requirement
-        ssa40B_1B = persons("social_security__residential_requirement", period.first_week)
-
-        ssa40B_1 = ssa40B_1A * ssa40B_1B * (ssa40B_1_a + ssa40B_1_b)
-
-        # 40B_2 specifies requirements for restricted work capacity status
 
-        # 40B_3 specifies requirements for restricted work capacity status
-
-        # 40B_4 (redundantly?) states that person P must be either totally blind or permanently disabled
-
-        # person P is ineligible if the disability was self-inflicted to gain benefits
-        ssa40B_5 = numpy.logical_not(persons("supported_living_payment__disability_self_inflicted", period))
-
-        return ssa40B_1 * ssa40B_5
-
-
-class supported_living_payment__carer__entitled(variables.Variable):
+class supported_living_payment__carer(variables.Variable):
     value_type = bool
     entity = entities.Person
     definition_period = periods.WEEK
     label = "Eligible for Supported Living Payment, on grounds of caring for another person."
-    reference = [
-        "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783187",
-        ]
-
-    def formula_2013_07_15(persons, period, parameters):
-        # person C is caring for person P
-        ssa40D_1 = persons("supported_living_payment__caring_for_another_person", period.first_week)
-
-        # person C is at least 18 years old if they have no dependent children
-        ssa40D_2_a = (persons("age", period.start) >= 18) * (persons("social_security__dependent_children", period.first_week) == 0)
-
-        # person C is at least 19 years old otherwise (i.e.: they have dependent children)
-        ssa40D_2_b = persons("age", period.start) >= 19
-
-        ssa40D_2 = ssa40D_2_a + ssa40D_2_b
-
-        # person C meets the residential requirement
-        ssa40D_3 = persons("social_security__residential_requirement", period.first_week)
-
-        # ssa40D_4 allows for payment to continue if not caring for 28 days
-
-        return ssa40D_1 * ssa40D_2 * ssa40D_3
-
-    def formula_2016_10_25(persons, period, parameters):
-        # person C is caring for person P
-        ssa40D_1 = persons("supported_living_payment__caring_for_another_person", period.first_week)
-
-        # person C is at least 18 years old if they have no dependent children
-        ssa40D_2_a = (persons("age", period.start) >= 18) * (persons("social_security__dependent_children", period.first_week) == 0)
-
-        # person C is at least 20 years old otherwise (i.e.: they have dependent children)
-        ssa40D_2_b = persons("age", period.start) >= 20
-
-        ssa40D_2 = ssa40D_2_a + ssa40D_2_b
-
-        # person C meets the residential requirement
-        ssa40D_3 = persons("social_security__residential_requirement", period.first_week)
-
-        # ssa40D_4 allows for payment to continue if not caring for 28 days
-
-        return ssa40D_1 * ssa40D_2 * ssa40D_3
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783187"
 
     def formula_2018_11_26(persons, period, parameters):
         # person C is caring for person P
@@ -193,10 +112,7 @@ class supported_living_payment__restricted_work_capacity(variables.Variable):
     entity = entities.Person
     definition_period = periods.WEEK
     label = "Is incapable of regularly working 15 or more hours a week in open employment"
-    reference = [
-        "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783176",
-        "http://legislation.govt.nz/act/public/1964/0136/latest/whole.html#DLM5468367",
-        ]
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783176"
     set_input = holders.set_input_dispatch_by_period
 
 
@@ -224,8 +140,8 @@ class supported_living_payment__caring_for_another_person(variables.Variable):
     entity = entities.Person
     definition_period = periods.WEEK
     label = "Eligible for Supported Living Payment."
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783187"
     set_input = holders.set_input_dispatch_by_period
+    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6783187"
 
 
 class supported_living_payment__disability_self_inflicted(variables.Variable):
diff --git a/openfisca_aotearoa/variables/acts/social_security/supported_living_payment/supported_living_payment__benefit.py b/openfisca_aotearoa/variables/acts/social_security/supported_living_payment/supported_living_payment__benefit.py
index 9c64b08b..5eaa627d 100644
--- a/openfisca_aotearoa/variables/acts/social_security/supported_living_payment/supported_living_payment__benefit.py
+++ b/openfisca_aotearoa/variables/acts/social_security/supported_living_payment/supported_living_payment__benefit.py
@@ -80,7 +80,7 @@ def formula_2018_11_26(population, period, parameters):
             numpy.clip(ssa_s4_7_gross_benefit, 0, clauses["clause_7_a"]),
             numpy.clip(ssa_s4_7_gross_benefit, 0, clauses["clause_7_b"]))
 
-        carer_entitled = population("supported_living_payment__carer__entitled", period, parameters)
+        carer_entitled = population("supported_living_payment__carer", period, parameters)
 
         # if the population is entitled as a carer, use the larger of c7 or other clauses
         benefit_post_c7 = numpy.where(
@@ -108,15 +108,17 @@ class supported_living_payment__assessable_income(variables.Variable):
     label = "The assessable income of the principle & partner for the purposes of income tests."
     reference = "https://legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6784861"
 
-    def formula_2018_11_26(population, period):
+    def formula_2018_11_26(population, period, parameters):
         # 1. Income for SLP on the basis of blindness or disability:
         #     (a) disregard that part of the beneficiary’s income (not exceeding $20 a week) earned by the beneficiary’s own efforts; and
         #     (b) disregard all of the income of a totally blind beneficiary earned by the beneficiary’s own efforts.
+        clauses = parameters(period.first_day).social_security.supported_living_payment.base.clauses
         gross_principal_income = population("social_security__income", period)
         principal_blind = population("totally_blind", period)
         principal_disabled = population("supported_living_payment__restricted_work_capacity", period)
         principal_abled = numpy.logical_not(numpy.logical_or(principal_blind, principal_disabled))
-        principal_disabled_income = gross_principal_income - (20 * period.size_in_weeks)
+        weekly_income_exempt = clauses["clause_1_income_disregarded"]
+        principal_disabled_income = gross_principal_income - (weekly_income_exempt * period.size_in_weeks)
         # income based on whether principal population members are blind, disabled, or neither
         assessable_principal_income = numpy.select(
             [principal_blind, principal_disabled, principal_abled],
@@ -159,7 +161,10 @@ class supported_living_payment__reduction(variables.Variable):
     entity = entities.Person
     definition_period = periods.WEEK
     label = "The amount the base benefit is reduced base on the appropriate Income Test and the person & their partners income"
-    reference = "https://legislation.govt.nz/act/public/2018/0032/latest/whole.html#DLM6784861"
+    reference = [
+        "https://www.legislation.govt.nz/act/public/2018/0032/56.0/DLM6784861.html",  # 2018-11-26
+        "https://www.legislation.govt.nz/act/public/2018/0032/140.0/DLM6784861.html",  # 2020-11-09
+        ]
 
     def formula_2018_11_26(population, period, parameters):
         family_income = population("supported_living_payment__assessable_income", period)
@@ -244,8 +249,11 @@ class supported_living_payment__base(variables.Variable):
     value_type = float
     entity = entities.Person
     definition_period = periods.WEEK
-    reference = "https://www.legislation.govt.nz/act/public/2018/0032/latest/DLM6784850.html"
     label = "Supported Living Payment - Base Amount, (this is taxed and the amounts are supplied after tax, i.e. net)"
+    reference = [
+        "https://www.legislation.govt.nz/act/public/2018/0032/56.0/DLM6784861.html",  # 2018-11-26
+        "https://www.legislation.govt.nz/act/public/2018/0032/140.0/DLM6784861.html",  # 2020-11-09
+        ]
 
     def formula_2018_11_26(population, period, parameters):
         clauses = parameters(period.first_day).social_security.supported_living_payment.base.clauses