MaxGhenis · Oct 5, 2026 · Oct 3, 2026 · Oct 3, 2026 · Oct 4, 2026
diff --git a/changelog.d/dead-urls-mi.fixed.md b/changelog.d/dead-urls-mi.fixed.md
@@ -0,0 +1 @@
+Replace dead Michigan Department of Treasury and Legislature reference URLs with live successors or pinned Wayback captures, and guard against their return.
diff --git a/policyengine_us/parameters/gov/contrib/states/mi/dependent_exemption/amount.yaml b/policyengine_us/parameters/gov/contrib/states/mi/dependent_exemption/amount.yaml
@@ -23,16 +23,16 @@ metadata:
   reference:
   # Legal code specified $3,700.
   - title: Michigan Legal Code Section 206.30 - (2)
-    href: http://legislature.mi.gov/doc.aspx?mcl-206-30
+    href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-30
   - title: Michigan Taxpayer's Guide 2022 - page 12
     href: https://www.legislature.mi.gov/Publications/TaxpayerGuide.pdf#page=12
   # 2021 manual contains values dating to 2017.
   - title: 2021 Michigan Taxpayer Assistance Manual - page 10
-    href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/UNCAT/2019_Taxpayer_Assistance_Manual.pdf#page=10
+    href: https://web.archive.org/web/20240512165124/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/UNCAT/2019_Taxpayer_Assistance_Manual.pdf#page=10
   - title: What is Michigan's 2023 personal exemption amount?
     href: https://www.michigan.gov/taxes/business-taxes/withholding/withholding-tax-faqs/what-is-michigans-2023-personal-exemption-amount
   - title: 2023 MI-1040 Instructions
-    href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040.pdf#page=3
+    href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2023/BOOK_MI-1040.pdf#page=3
   - title: Michigan 2024 Individual Income Tax Instructions, Line 9a
     href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040-Instructions.pdf#page=13
   - title: Michigan 2025 Income Tax Withholding Guide (Form 446)

diff --git a/policyengine_us/parameters/gov/states/mi/tax/income/additions.yaml b/policyengine_us/parameters/gov/states/mi/tax/income/additions.yaml
@@ -9,12 +9,12 @@ metadata:
   period: year  
   reference:
     - title: 2022 Michigan Schedule 1 Additions and Subtractions
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2022/2022-IIT-Forms/Schedule-1.pdf
+      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2022/Schedule-1.pdf
     - title: 2023 Michigan Schedule 1 Additions and Subtractions
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040.pdf#page=47
+      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2023/BOOK_MI-1040.pdf#page=47
     - title: Michigan 2022 MI-1040 Individual Income Tax FORMS AND INSTRUCTIONS
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2022/2022-IIT-Forms/BOOK_MI-1040.pdf#page=12
+      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2022/BOOK_MI-1040.pdf#page=12
     - title: Michigan 2023 MI-1040 Individual Income Tax FORMS AND INSTRUCTIONS
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040.pdf#page=13
+      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2023/BOOK_MI-1040.pdf#page=13
     - title: Michigan 2024 Indiviudal Income Tax Instructions
       href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040-Instructions.pdf#page=13
diff --git a/policyengine_us/parameters/gov/states/mi/tax/income/credits/eitc/match.yaml b/policyengine_us/parameters/gov/states/mi/tax/income/credits/eitc/match.yaml
@@ -5,11 +5,11 @@ metadata:
   label: Michigan EITC match 
   reference:
     - title: INCOME TAX ACT OF 1967 - Section 206.272, (1)
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-272
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-272
     - title: 2022 MICHIGAN Individual Income Tax Return MI-1040 Form, Line 27
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2022/2022-IIT-Forms/MI-1040.pdf#page=2
+      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2022/MI-1040.pdf#page=2
     - title: 2023 MICHIGAN Individual Income Tax Return MI-1040 Form, Line 27
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/MI-1040.pdf#page=2
+      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2023/MI-1040.pdf#page=2
     - title: Michigan 2024 Individual Income Tax Instructions, Line 27
       href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040-Instructions.pdf#page=11
     - title: Michigan 2025 Individual Income Tax Instructions, Line 27

diff --git a/...parameters/gov/states/mi/tax/income/credits/home_heating/additional_exemption/amount.yaml b/...parameters/gov/states/mi/tax/income/credits/home_heating/additional_exemption/amount.yaml
@@ -12,12 +12,12 @@ metadata:
   label: Michigan home heating additional base amount per additional exemption
   reference:
     - title: Michigan Section 206.527a, Income Tax Act of 1967(Exerpt)Act 281 of 1967, (1)(a)
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-527a
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-527a
     - title: Michigan 2021 Book MI-1040CR7 Home Heating Instructions, Table A
-      href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20220523104347/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf?rev=d7990c15e0034d768a43c47b6d3ba0ac#page=11
     - title: Michigan 2022 MI-1040CR7 Home Heating Credit Claim Instructions, Table A
       href: https://www.efile.com/pdf/5988.pdf#page=13
     - title: Michigan 2023 Book MI-1040CR7 Home Heating Instructions, Table A
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20240928005701/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf?rev=048b871ae3294dec8ca7761afb2d8f78&hash=C3FFD92D4D764FFFE75A88FE25F09C97#page=11
     - title: Michigan 2024 Book MI-1040CR7 Home Heating Instructions, Table A
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20250202150154/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/BOOK_MI-1040CR-7.pdf#page=11
diff --git a/.../parameters/gov/states/mi/tax/income/credits/home_heating/additional_exemption/limit.yaml b/.../parameters/gov/states/mi/tax/income/credits/home_heating/additional_exemption/limit.yaml
@@ -7,13 +7,13 @@ metadata:
   label: Michigan home heating credit additional exemption limit
   reference:
     - title: Michigan Section 206.527a, Income Tax Act of 1967(Exerpt)Act 281 of 1967, (1)(a)
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-527a
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-527a
     - title: Michigan 2021 Book MI-1040CR7 Home Heating Instructions, Table A
-      href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20220523104347/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf?rev=d7990c15e0034d768a43c47b6d3ba0ac#page=11
     - title: Michigan 2022 MI-1040CR7 Home Heating Credit Claim Instructions, Table A
       href: https://www.efile.com/pdf/5988.pdf#page=13
     - title: Michigan 2023 Book MI-1040CR7 Home Heating Instructions, Table A
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20240928005701/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf?rev=048b871ae3294dec8ca7761afb2d8f78&hash=C3FFD92D4D764FFFE75A88FE25F09C97#page=11
     - title: Michigan 2024 Book MI-1040CR7 Home Heating Instructions, Table A
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20250202150154/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/BOOK_MI-1040CR-7.pdf#page=11
 
diff --git a/...parameters/gov/states/mi/tax/income/credits/home_heating/alternate/heating_costs/cap.yaml b/...parameters/gov/states/mi/tax/income/credits/home_heating/alternate/heating_costs/cap.yaml
@@ -13,12 +13,12 @@ metadata:
   reference:
     # The exact cap amount is not specified in the law, only the yearly inflation adjustment
     - title: Michigan Section 206.527a, Income Tax Act of 1967(Exerpt)Act 281 of 1967, (1)(d)
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-527a
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-527a
     - title: 2021 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 42
-      href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20220523121258/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/MI-1040CR7.pdf?rev=84f72df3f8664b96903aa6b655dc34d2#page=2
     - title: 2022 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 42
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2022/2022-IIT-Forms/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20230321124541/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2022/2022-IIT-Forms/MI-1040CR7.pdf#page=2
     - title: 2023 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 42
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20240812191051/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/MI-1040CR7.pdf#page=2
     - title: 2024 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 42
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040CR-7.pdf#page=2
+      href: https://web.archive.org/web/20250202222033/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040CR-7.pdf#page=2
diff --git a/...arameters/gov/states/mi/tax/income/credits/home_heating/alternate/heating_costs/rate.yaml b/...arameters/gov/states/mi/tax/income/credits/home_heating/alternate/heating_costs/rate.yaml
@@ -7,12 +7,12 @@ metadata:
   label: Michigan alternate home heating credit household resource rate
   reference:
     - title: Michigan Section 206.527a, Income Tax Act of 1967(Exerpt)Act 281 of 1967, (1)(c)(ii)
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-527a
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-527a
     - title: 2021 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 45
-      href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20220523121258/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/MI-1040CR7.pdf?rev=84f72df3f8664b96903aa6b655dc34d2#page=2
     - title: 2022 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 45
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2022/2022-IIT-Forms/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20230321124541/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2022/2022-IIT-Forms/MI-1040CR7.pdf#page=2
     - title: 2023 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 45
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20240812191051/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/MI-1040CR7.pdf#page=2
     - title: 2024 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 45
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040CR-7.pdf#page=2
+      href: https://web.archive.org/web/20250202222033/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040CR-7.pdf#page=2
diff --git a/...ters/gov/states/mi/tax/income/credits/home_heating/alternate/household_resources/cap.yaml b/...ters/gov/states/mi/tax/income/credits/home_heating/alternate/household_resources/cap.yaml
@@ -7,15 +7,15 @@ metadata:
   reference:
     # Legal Code diverges from the tax form - here we model the tax form structure
     - title: Michigan Section 206.527a, Income Tax Act of 1967(Exerpt)Act 281 of 1967, (1)(c)(ii)
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-527a
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-527a
     - title: Michigan 2021 Book MI-1040CR7 Home Heating Instructions, Table B
-      href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20220523104347/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf?rev=d7990c15e0034d768a43c47b6d3ba0ac#page=11
     - title: Michigan 2022 MI-1040CR7 Home Heating Credit Claim Instructions, Table B
       href: https://www.efile.com/pdf/5988.pdf#page=13
     - title: Michigan 2023 Book MI-1040CR7 Home Heating Instructions, Table B
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20240928005701/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf?rev=048b871ae3294dec8ca7761afb2d8f78&hash=C3FFD92D4D764FFFE75A88FE25F09C97#page=11
     - title: Michigan 2024 Book MI-1040CR7 Home Heating Instructions, Table B
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20250202150154/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/BOOK_MI-1040CR-7.pdf#page=11
 
 brackets:
   - threshold:

diff --git a/...ers/gov/states/mi/tax/income/credits/home_heating/alternate/household_resources/rate.yaml b/...ers/gov/states/mi/tax/income/credits/home_heating/alternate/household_resources/rate.yaml
@@ -7,12 +7,12 @@ metadata:
   label: Michigan home heating credit alternate household resource rate
   reference:
     - title: Michigan Section 206.527a, Income Tax Act of 1967(Exerpt)Act 281 of 1967, (1)(c)(ii)
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-527a
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-527a
     - title: 2021 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 43
-      href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20220523121258/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/MI-1040CR7.pdf?rev=84f72df3f8664b96903aa6b655dc34d2#page=2
     - title: 2022 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 43
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2022/2022-IIT-Forms/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20230321124541/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2022/2022-IIT-Forms/MI-1040CR7.pdf#page=2
     - title: 2023 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 43
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20240812191051/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/MI-1040CR7.pdf#page=2
     - title: 2024 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 43
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040CR-7.pdf#page=2
+      href: https://web.archive.org/web/20250202222033/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040CR-7.pdf#page=2
diff --git a/...engine_us/parameters/gov/states/mi/tax/income/credits/home_heating/credit_percentage.yaml b/...engine_us/parameters/gov/states/mi/tax/income/credits/home_heating/credit_percentage.yaml
@@ -12,20 +12,20 @@ metadata:
   label: Michigan home heating credit percentage
   reference:
     - title: Michigan Section 206.527a, Income Tax Act of 1967(Exerpt)Act 281 of 1967
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-527a
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-527a
     - title: 2021 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 47
-      href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20220523121258/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/MI-1040CR7.pdf?rev=84f72df3f8664b96903aa6b655dc34d2#page=2
     - title: 2022 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 47
       href: https://www.semcoenergygas.com/wp-content/uploads/2022-MI-1040CR7.pdf#page=2
     - title: 2023 MICHIGAN Home Heating Credit Claim MI-1040CR-7, Line 47
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/MI-1040CR7.pdf#page=2
+      href: https://web.archive.org/web/20240812191051/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/MI-1040CR7.pdf#page=2
     - title: Michigan 2021 Book MI-1040CR7 Home Heating Instructions Line 47
-      href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf#page=9
+      href: https://web.archive.org/web/20220523104347/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf?rev=d7990c15e0034d768a43c47b6d3ba0ac#page=9
     - title: Michigan 2022 MI-1040CR7 Home Heating Credit Claim Instructions, Line 47
       href: https://www.efile.com/pdf/5988.pdf#page=11
     - title: Michigan 2023 Book MI-1040CR7 Home Heating Instructions Line 47
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf#page=9
+      href: https://web.archive.org/web/20240928005701/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf?rev=048b871ae3294dec8ca7761afb2d8f78&hash=C3FFD92D4D764FFFE75A88FE25F09C97#page=9
     - title: 2024 Michigan Home Heating Credit Claim MI-1040CR-7 Line 47
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040CR-7.pdf#page=2
+      href: https://web.archive.org/web/20250202222033/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/MI-1040CR-7.pdf#page=2
     - title: 2025 Michigan Home Heating Credit Claim Instructions, Line 45
       href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2025/MI-1040CR-7-Book.pdf#page=10
diff --git a/policyengine_us/parameters/gov/states/mi/tax/income/credits/home_heating/standard/base.yaml b/policyengine_us/parameters/gov/states/mi/tax/income/credits/home_heating/standard/base.yaml
@@ -7,15 +7,15 @@ metadata:
   reference:
     # The legal code provides inflation undajusted amounts
     - title: Michigan Section 206.527a, Income Tax Act of 1967(Exerpt)Act 281 of 1967, (1)(a)
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-527a
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-527a
     - title: Michigan 2021 Book MI-1040CR7 Home Heating Instructions, Table A
-      href: https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20220523104347/https://www.michigan.gov/-/media/Project/Websites/taxes/2022RM/IIT/BOOK_MI-1040CR-7.pdf?rev=d7990c15e0034d768a43c47b6d3ba0ac#page=11
     - title: Michigan 2022 MI-1040CR7 Home Heating Credit Claim Instructions, Table A
       href: https://www.efile.com/pdf/5988.pdf#page=13
     - title: Michigan 2023 Book MI-1040CR7 Home Heating Instructions, Table A
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20240928005701/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/2023/2023-IIT-Forms/BOOK_MI-1040CR-7.pdf?rev=048b871ae3294dec8ca7761afb2d8f78&hash=C3FFD92D4D764FFFE75A88FE25F09C97#page=11
     - title: Michigan 2024 Book MI-1040CR7 Home Heating Instructions, Table A
-      href: https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/BOOK_MI-1040CR-7.pdf#page=11
+      href: https://web.archive.org/web/20250202150154/https://www.michigan.gov/taxes/-/media/Project/Websites/taxes/Forms/IIT/TY2024/BOOK_MI-1040CR-7.pdf#page=11
 brackets:
   - threshold:
       2021-01-01: 0

diff --git a/...engine_us/parameters/gov/states/mi/tax/income/credits/home_heating/standard/fpg_rate.yaml b/...engine_us/parameters/gov/states/mi/tax/income/credits/home_heating/standard/fpg_rate.yaml
@@ -5,7 +5,7 @@ metadata:
   label: Michigan standard home heating credit federal poverty guidelines rate
   reference:
     - title: Michigan Section 206.527a, Income Tax Act of 1967(Exerpt)Act 281 of 1967, (1)(b)
-      href: http://legislature.mi.gov/doc.aspx?mcl-206-527a
+      href: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-206-527a
 
 values:
   2021-01-01: 1.1
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Replace dead Michigan Department of Treasury and Legislature reference URLs with live successors or pinned Wayback captures, and guard against their return.