diff --git a/changelog.d/hb-special-disregard.added.md b/changelog.d/hb-special-disregard.added.md
new file mode 100644
index 0000000000..8a9d2c8319
--- /dev/null
+++ b/changelog.d/hb-special-disregard.added.md
@@ -0,0 +1 @@
+Added the Housing Benefit special standard earnings disregard with regime-specific qualifying routes, explicit residual pre-assessment and no stacking with ordinary amounts.
diff --git a/policyengine_uk/parameters/gov/dwp/housing_benefit/means_test/income_disregard/special.yaml b/policyengine_uk/parameters/gov/dwp/housing_benefit/means_test/income_disregard/special.yaml
new file mode 100644
index 0000000000..e1f45b0c7d
--- /dev/null
+++ b/policyengine_uk/parameters/gov/dwp/housing_benefit/means_test/income_disregard/special.yaml
@@ -0,0 +1,16 @@
+description: Weekly Housing Benefit special standard earnings disregard, replacing the ordinary single or couple amount.
+values:
+  2015-04-01: 20
+metadata:
+  period: week
+  unit: currency-GBP
+  label: Housing Benefit special earnings disregard
+  reference:
+    - title: GB working-age earnings disregards, paragraphs 3 and 5 to 9
+      href: https://www.legislation.gov.uk/uksi/2006/213/schedule/4
+    - title: GB pension-age earnings disregards, paragraphs 1 to 7
+      href: https://www.legislation.gov.uk/uksi/2006/214/schedule/4
+    - title: NI working-age earnings disregards
+      href: https://www.legislation.gov.uk/nisr/2006/405/schedule/5
+    - title: NI pension-age earnings disregards
+      href: https://www.legislation.gov.uk/nisr/2006/406/schedule/5
diff --git a/policyengine_uk/tests/policy/baseline/finance/benefit/family/housing_benefit/applicable_income/housing_benefit_applicable_income_disregard.yaml b/policyengine_uk/tests/policy/baseline/finance/benefit/family/housing_benefit/applicable_income/housing_benefit_applicable_income_disregard.yaml
index 7cf5e90192..a2dcadd7cd 100644
--- a/policyengine_uk/tests/policy/baseline/finance/benefit/family/housing_benefit/applicable_income/housing_benefit_applicable_income_disregard.yaml
+++ b/policyengine_uk/tests/policy/baseline/finance/benefit/family/housing_benefit/applicable_income/housing_benefit_applicable_income_disregard.yaml
@@ -430,7 +430,7 @@
     # One member must work 30 hours; hours are not added across the couple.
     housing_benefit_applicable_income_disregard: 520 # £10 × 52
 
-- name: Disabled single person working 20 hours gets £5 plus the additional disregard (model limitation; the law gives £20 plus it)
+- name: Disabled single person working 20 hours gets £20 plus the additional disregard
   period: 2026
   absolute_error_margin: 0.01
   input:
@@ -448,15 +448,13 @@
     # Para 17(2)(b)(iv)(aa): a single claimant with the disability premium
     # working 16 hours or more meets the condition.
     meets_housing_benefit_additional_earnings_disregard_conditions: true
-    # KNOWN LIMITATION: the law gives £1,929.20. Intended model limitation.
-    # In law the same disability premium brings in
-    # the £20 disregard in place of £5: Sch 4 para 3(2), "This paragraph
-    # applies where the claimant's applicable amount includes an amount by
-    # way of the disability premium". The law gives (£20 + £17.10) × 52 =
-    # £1,929.20 (£8,000 ≥ £1,040 + £889.20). The £20 disregards are out of
-    # scope for this change and tracked as a follow-up; until then the model
-    # gives (£5 + £17.10) × 52.
-    housing_benefit_applicable_income_disregard: 1_149.20
+    # The disability premium gives the £20 standard disregard under Sch 4
+    # para 3(2), replacing £5. Net earnings cover that amount and the
+    # additional disregard: £8,000 ≥ £1,040 + £889.20.
+    # (£20 + £17.10) × 52 = £1,929.20.
+    # https://www.legislation.gov.uk/uksi/2006/213/schedule/4/paragraph/3
+    # https://www.legislation.gov.uk/uksi/2006/213/schedule/4/paragraph/17
+    housing_benefit_applicable_income_disregard: 1_929.20
 
 - name: Working-age claimant on Income Support has all earnings disregarded
   period: 2026
diff --git a/policyengine_uk/tests/policy/baseline/finance/benefit/family/housing_benefit/applicable_income/housing_benefit_special_disregard.yaml b/policyengine_uk/tests/policy/baseline/finance/benefit/family/housing_benefit/applicable_income/housing_benefit_special_disregard.yaml
new file mode 100644
index 0000000000..af71a63ef8
--- /dev/null
+++ b/policyengine_uk/tests/policy/baseline/finance/benefit/family/housing_benefit/applicable_income/housing_benefit_special_disregard.yaml
@@ -0,0 +1,104 @@
+# Cases: working disability/severe; working carer-only; pension carer;
+# pension generic disability premium; pension/working DLA; non-dependant DLA;
+# pension/working blindness.
+- name: ENGLAND statutory regime distinguishes automatic qualifying routes
+  period: 2024
+  input:
+    country: [ENGLAND, ENGLAND, ENGLAND, ENGLAND, ENGLAND, ENGLAND, ENGLAND, ENGLAND, ENGLAND, ENGLAND]
+    housing_benefit_pension_age_regulations_apply: [false, false, false, true, true, true, false, true, true, false]
+    disability_premium: [100, 0, 0, 0, 100, 0, 0, 0, 0, 0]
+    severe_disability_premium: [0, 100, 0, 0, 0, 0, 0, 0, 0, 0]
+    carer_premium: [0, 0, 100, 100, 0, 0, 0, 0, 0, 0]
+    dla_sc: [0, 0, 0, 0, 0, 100, 100, 100, 0, 0]
+    dla_m: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    pip_dl: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    pip_m: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    attendance_allowance: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    armed_forces_independence_payment: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    is_blind: [false, false, false, false, false, false, false, false, true, true]
+    is_claimant_or_partner: [true, true, true, true, true, true, true, false, true, true]
+    housing_benefit_net_earnings: [5000, 5000, 5000, 5000, 5000, 5000, 5000, 5000, 5000, 5000]
+    is_lone_parent: [false, false, false, false, false, false, false, false, false, false]
+    is_couple: [false, false, false, false, false, false, false, false, false, false]
+  output:
+    housing_benefit_special_earnings_disregard_eligible: [true, true, false, true, false, true, false, false, true, false]
+    housing_benefit_special_earnings_disregard: [1040, 1040, 260, 1040, 260, 1040, 260, 260, 1040, 260]
+
+# Cases: working disability/severe; working carer-only; pension carer;
+# pension generic disability premium; pension/working DLA; non-dependant DLA;
+# pension/working blindness.
+- name: NORTHERN_IRELAND statutory regime distinguishes automatic qualifying routes
+  period: 2024
+  input:
+    country: [NORTHERN_IRELAND, NORTHERN_IRELAND, NORTHERN_IRELAND, NORTHERN_IRELAND, NORTHERN_IRELAND, NORTHERN_IRELAND, NORTHERN_IRELAND, NORTHERN_IRELAND, NORTHERN_IRELAND, NORTHERN_IRELAND]
+    housing_benefit_pension_age_regulations_apply: [false, false, false, true, true, true, false, true, true, false]
+    disability_premium: [100, 0, 0, 0, 100, 0, 0, 0, 0, 0]
+    severe_disability_premium: [0, 100, 0, 0, 0, 0, 0, 0, 0, 0]
+    carer_premium: [0, 0, 100, 100, 0, 0, 0, 0, 0, 0]
+    dla_sc: [0, 0, 0, 0, 0, 100, 100, 100, 0, 0]
+    dla_m: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    pip_dl: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    pip_m: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    attendance_allowance: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    armed_forces_independence_payment: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    is_blind: [false, false, false, false, false, false, false, false, true, true]
+    is_claimant_or_partner: [true, true, true, true, true, true, true, false, true, true]
+    housing_benefit_net_earnings: [5000, 5000, 5000, 5000, 5000, 5000, 5000, 5000, 5000, 5000]
+    is_lone_parent: [false, false, false, false, false, false, false, false, false, false]
+    is_couple: [false, false, false, false, false, false, false, false, false, false]
+  output:
+    housing_benefit_special_earnings_disregard_eligible: [true, true, false, true, false, true, false, false, true, false]
+    housing_benefit_special_earnings_disregard: [1040, 1040, 260, 1040, 260, 1040, 260, 260, 1040, 260]
+
+- name: Standard replacement, lone-parent precedence and earnings cap
+  period: 2024
+  input:
+    housing_benefit_special_earnings_disregard_eligible: [true, true, true, true, false, false]
+    housing_benefit_net_earnings: [5000, 5000, 5000, 500, 5000, 5000]
+    is_couple: [false, true, false, true, false, true]
+    is_lone_parent: [false, false, true, false, false, false]
+    housing_benefit_specified_or_temporary_accommodation_disregard: [0, 0, 0, 0, 0, 0]
+    housing_benefit_applicable_income_childcare_element: [0, 0, 0, 0, 0, 0]
+    meets_housing_benefit_additional_earnings_disregard_conditions: [false, false, false, false, false, false]
+    housing_benefit_on_passporting_benefit: [false, false, false, false, false, false]
+  output:
+    housing_benefit_applicable_income_disregard: [1040, 1040, 1300, 500, 260, 520]
+
+- name: Special standard amount participates in additional-disregard threshold
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    housing_benefit_special_earnings_disregard_eligible: [true, true, true]
+    housing_benefit_net_earnings: [1929.19, 1929.20, 5000]
+    is_couple: [false, true, false]
+    is_lone_parent: [false, false, false]
+    housing_benefit_specified_or_temporary_accommodation_disregard: [0, 0, 0]
+    housing_benefit_applicable_income_childcare_element: [0, 0, 0]
+    meets_housing_benefit_additional_earnings_disregard_conditions: [true, true, true]
+    housing_benefit_on_passporting_benefit: [false, false, true]
+  output:
+    housing_benefit_applicable_income_disregard: [1040, 1929.20, 5000]
+
+- name: A zero special-amount reform is not replaced with the ordinary amount
+  period: 2024
+  input:
+    gov.dwp.housing_benefit.means_test.income_disregard.special: 0
+    housing_benefit_special_earnings_disregard_eligible: true
+    housing_benefit_net_earnings: 5000
+    is_lone_parent: false
+    is_couple: true
+  output:
+    housing_benefit_special_earnings_disregard: 0
+
+- name: Missing residual qualification preserves ordinary treatment
+  period: 2024
+  input:
+    disability_premium: 0
+    severe_disability_premium: 0
+    housing_benefit_pension_age_regulations_apply: false
+    housing_benefit_net_earnings: 5000
+    is_lone_parent: false
+    is_couple: false
+  output:
+    housing_benefit_special_earnings_disregard_eligible: false
+    housing_benefit_special_earnings_disregard: 260
diff --git a/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_applicable_income_disregard.py b/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_applicable_income_disregard.py
index a7600bf518..7de5c94a3d 100644
--- a/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_applicable_income_disregard.py
+++ b/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_applicable_income_disregard.py
@@ -20,10 +20,11 @@ class housing_benefit_applicable_income_disregard(Variable):
         "(housing_benefit_on_passporting_benefit) has all earnings "
         "disregarded, at any age: the working-age Regulations then apply "
         "(SI 2006/213 reg 5(1)(b)). The "
-        "£20 disregards for disabled people, carers and some part-time "
-        "occupations are not modelled, nor is the working-age permitted work "
+        "£20 standard disregard uses established qualifying routes or an "
+        "explicit full-amount pre-assessment, without reconstructing partial "
+        "carer/occupation earnings allocations. The permitted-work "
         "disregard (Sch 4 para 10A), which replaces paras 3 to 10 but not "
-        "para 18."
+        "para 18, is not yet modelled here."
     )
     definition_period = YEAR
     unit = GBP
@@ -42,12 +43,7 @@ def formula(benunit, period, parameters):
         p = parameters(period).gov.dwp.housing_benefit.means_test.income_disregard
         net_earnings = benunit("housing_benefit_net_earnings", period)
         # Working age Sch 4 paras 4, 7 and 10; pension age Sch 4 paras 2 and 7.
-        weekly_amount = select(
-            [benunit("is_lone_parent", period), benunit("is_couple", period)],
-            [p.lone_parent, p.couple],
-            default=p.single,
-        )
-        standard = min_(weekly_amount * WEEKS_IN_YEAR, net_earnings)
+        standard = benunit("housing_benefit_special_earnings_disregard", period)
         # Working age Sch 4 para 18 (NI Sch 5 para 18), from 5 October 2026:
         # specified or temporary accommodation. It applies alongside paras 3
         # to 10A, none of which excludes it, and takes the earnings they
diff --git a/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_special_earnings_disregard.py b/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_special_earnings_disregard.py
new file mode 100644
index 0000000000..04d731487a
--- /dev/null
+++ b/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_special_earnings_disregard.py
@@ -0,0 +1,37 @@
+from policyengine_uk.model_api import *
+
+
+class housing_benefit_special_earnings_disregard(Variable):
+    value_type = float
+    entity = BenUnit
+    definition_period = YEAR
+    unit = GBP
+    label = "Housing Benefit selected standard earnings disregard"
+    documentation = (
+        "Standard disregard selected before the additional/accommodation "
+        "amounts: lone-parent precedence, otherwise the special amount for "
+        "a qualifying family, otherwise the ordinary couple/single amount. "
+        "It is a replacement, not £20 added to £5 or £10. The total standard "
+        "deduction is capped at the claimant's and partner's net earnings."
+    )
+    reference = (
+        "https://www.legislation.gov.uk/uksi/2006/213/schedule/4",
+        "https://www.legislation.gov.uk/uksi/2006/214/schedule/4",
+        "https://www.legislation.gov.uk/nisr/2006/405/schedule/5",
+        "https://www.legislation.gov.uk/nisr/2006/406/schedule/5",
+    )
+
+    def formula(benunit, period, parameters):
+        p = parameters(period).gov.dwp.housing_benefit.means_test.income_disregard
+        weekly = select(
+            [
+                benunit("is_lone_parent", period),
+                benunit("housing_benefit_special_earnings_disregard_eligible", period),
+                benunit("is_couple", period),
+            ],
+            [p.lone_parent, p.special, p.couple],
+            default=p.single,
+        )
+        return min_(
+            weekly * WEEKS_IN_YEAR, benunit("housing_benefit_net_earnings", period)
+        )
diff --git a/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_special_earnings_disregard_eligible.py b/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_special_earnings_disregard_eligible.py
new file mode 100644
index 0000000000..5c15427da6
--- /dev/null
+++ b/policyengine_uk/variables/gov/dwp/housing_benefit/applicable_income/housing_benefit_special_earnings_disregard_eligible.py
@@ -0,0 +1,61 @@
+from policyengine_uk.model_api import *
+
+
+class housing_benefit_special_earnings_disregard_eligible(Variable):
+    value_type = bool
+    entity = BenUnit
+    definition_period = YEAR
+    default_value = False
+    label = "Qualifies for the full Housing Benefit special earnings disregard"
+    documentation = (
+        "Whether the full special standard amount may legally be deducted "
+        "from the benefit unit's combined earnings, subject to the earnings "
+        "cap. Derived for working-age disability/severe-premium routes and "
+        "pension-age qualifying benefit receipt, blindness or carer premium. "
+        "Other full-amount routes may be pre-assessed as an input, including "
+        "the applicable job/partner earnings allocation: mere occupation or "
+        "carer status is not sufficient. Partial carer/occupation allocations "
+        "below the full amount are not reconstructed by this Boolean. Existing "
+        "premium/benefit qualification approximations are inherited. No "
+        "dataset mapping for residual pre-assessment is verified; a false "
+        "fallback may omit qualifying ESA phase/history/occupation routes."
+    )
+    reference = (
+        "https://www.legislation.gov.uk/uksi/2006/213/schedule/4",
+        "https://www.legislation.gov.uk/uksi/2006/214/schedule/4",
+        "https://www.legislation.gov.uk/nisr/2006/405/schedule/5",
+        "https://www.legislation.gov.uk/nisr/2006/406/schedule/5",
+    )
+
+    def formula(benunit, period, parameters):
+        working = (benunit("disability_premium", period) > 0) | (
+            benunit("severe_disability_premium", period) > 0
+        )
+        person = benunit.members
+        qualifying_receipt = (
+            add(
+                person,
+                period,
+                [
+                    "attendance_allowance",
+                    "dla_sc",
+                    "dla_m",
+                    "pip_dl",
+                    "pip_m",
+                    "armed_forces_independence_payment",
+                ],
+            )
+            > 0
+        )
+        pension = benunit.any(
+            person("is_claimant_or_partner", period)
+            & (qualifying_receipt | person("is_blind", period))
+        ) | (benunit("carer_premium", period) > 0)
+        # Working-age carer/occupation routes restrict which person's/job's
+        # earnings may be disregarded. Do not automatically apply £20 to an
+        # ordinary earner solely because their non-earning partner cares.
+        return where(
+            benunit("housing_benefit_pension_age_regulations_apply", period),
+            pension,
+            working,
+        )