Merge pull request #3068 from martinholmer/6-6-0

Prepare release 6.6.0

Author: jdebacker

docs/about/releases.md

@@ -5,6 +5,55 @@ Go
 for a complete commit history.
 
 
+2026-05-18 Release 6.6.0
+------------------------
+(last merged pull request is
+[#3067](https://github.com/PSLmodels/Tax-Calculator/pull/3067))
+
+**This is an enhancement and bug-fix release.**
+
+**API Changes**
+
+**New Features**
+- Extensive `calcfunctions.py` code review that improves the correspondence
+  of Python code and local variable names with 2025 IRS tax forms (while
+  maintaining legacy/reform tax logic) and improves `calcfunctions.py`
+  documentation.
+  [[#3016](https://github.com/PSLmodels/Tax-Calculator/pull/3016)
+   through
+   [#3067](https://github.com/PSLmodels/Tax-Calculator/pull/3067)
+   by Martin Holmer with the assistance of Claude Code 2.1 running Opus 4.7]
+- Rename calculated variable `dwks19` as `dwks18` to match 2025 IRS form
+  line number.
+  [[#3024](https://github.com/PSLmodels/Tax-Calculator/pull/3024)
+   by Martin Holmer with the assistance of Claude Code]
+- Rename policy parameter `ALD_AlimonyReceived_hc` as
+  `AlimonyReceived_frac_in_AGI`.
+  [[#3026](https://github.com/PSLmodels/Tax-Calculator/pull/3026)
+   by Martin Holmer with the assistance of Claude Code]
+- Add policy parameter `STD_Dep_earned_add` and use in `StdDed` function logic.
+  [[#3040](https://github.com/PSLmodels/Tax-Calculator/pull/3040)
+   by Martin Holmer with the assistance of Claude Code]
+
+**Bug Fixes**
+- Extensive `calcfunctions.py` code review identified and fixed
+  several tax logic bugs, all of which had tiny effects on aggregate
+  income tax liability; only bug fixes that had a measurable effect on
+  2026 current-law liability (using TMD input data) are mentioned below.
+  [[#3016](https://github.com/PSLmodels/Tax-Calculator/pull/3016)
+   through
+   [#3067](https://github.com/PSLmodels/Tax-Calculator/pull/3067)
+   by Martin Holmer with the assistance of Claude Code 2.1 running Opus 4.7]
+- Fix QBID bugs in `TaxIncome` function.  Effect:
+    tmd-26.tables: 2644.3 → 2645.3 (+0.04 percent relative change).
+  [[#3042](https://github.com/PSLmodels/Tax-Calculator/pull/3042)
+   by Martin Holmer with the assistant of Claude Code]
+- Fix `AMT` function bugs.  Effect:
+   tmd-26.tables: 2645.3 → 2644.0 (-0.05 percent relative change).
+  [[#3049](https://github.com/PSLmodels/Tax-Calculator/pull/3049)
+   by Martin Holmer with the assistant of Claude Code]
+
+
 2026-04-27 Release 6.5.3
 ------------------------
 (last merged pull request is

docs/index.md

@@ -50,7 +50,7 @@ cross-model validation work with NBER's TAXSIM-35 model is described
 
 ## Latest release
 
-{doc}`6.5.3 (2026-04-27) <about/releases>`
+{doc}`6.6.0 (2026-05-18) <about/releases>`
 
 If you are already using Tax-Calculator, upgrade using the following command:
 ```

setup.py

@@ -7,7 +7,7 @@
 with open("README.md", "r", encoding="utf-8") as f:
     longdesc = f.read()
 
-VERSION = "6.5.3"
+VERSION = "6.6.0"
 
 config = {
     "description": "Tax-Calculator",

taxcalc.egg-info/PKG-INFO

@@ -1,6 +1,6 @@
 Metadata-Version: 2.4
 Name: taxcalc
-Version: 6.5.3
+Version: 6.6.0
 Summary: Tax-Calculator
 Home-page: https://github.com/PSLmodels/Tax-Calculator
 Download-URL: https://github.com/PSLmodels/Tax-Calculator

taxcalc/__init__.py

@@ -14,6 +14,6 @@
 from taxcalc.utils import *
 from taxcalc.cli import *
 
-__version__ = '6.5.3'
+__version__ = '6.6.0'
 __min_python3_version__ = 11
 __max_python3_version__ = 13

taxcalc/policy_current_law.json

@@ -996,7 +996,7 @@
     },
     "ALD_Tuition_hc": {
         "title": "Deduction for tuition and fees haircut",
-        "description": "If greater than zero, this decimal fraction reduces the portion of tuition and fees that can be deducted from AGI.  The final adjustment amount would be (1-Haircut)*TuitionFees.  Set to 1.0 starting 2021: IRC §222 was permanently repealed for tax years beginning after 2020-12-31 by §104 of the Taxpayer Certainty and Disaster Tax Relief Act of 2020.",
+        "description": "If greater than zero, this decimal fraction reduces the portion of tuition and fees that can be deducted from AGI.  The final adjustment amount would be (1-Haircut)*TuitionFees.  Set to 1.0 starting 2021: IRC Section 222 was permanently repealed for tax years beginning after 2020-12-31 by Section 104 of the Taxpayer Certainty and Disaster Tax Relief Act of 2020.",
         "section_1": "Above The Line Deductions",
         "section_2": "Misc. Adjustment Haircuts",
         "indexable": false,
@@ -2654,7 +2654,7 @@
     },
     "STD_Dep_earned_add": {
         "title": "Earned-income additional amount in dependent standard deduction",
-        "description": "In the IRS Standard Deduction Worksheet for Dependents (Form 1040 instructions), this is the amount added to earned income (worksheet line 2) before comparing against the minimum dependent standard deduction (STD_Dep). Indexed for inflation per IRC §63(c)(5)(B).",
+        "description": "In the IRS Standard Deduction Worksheet for Dependents (Form 1040 instructions), this is the amount added to earned income (worksheet line 2) before comparing against the minimum dependent standard deduction (STD_Dep). Indexed for inflation per IRC Section 63(c)(5)(B).",
         "section_1": "",
         "section_2": "",
         "indexable": true,

update_pcl.py

@@ -540,6 +540,15 @@
 
         {'year': 2026, 'value': 1350.0},
     ],
+    'STD_Dep_earned_add': [
+        {'year': 2023, 'value': 400.0},
+
+        {'year': 2024, 'value': 450.0},
+
+        {'year': 2025, 'value': 450.0},
+
+        {'year': 2026, 'value': 450.0},
+    ],
     'STD_Aged': [
         {'year': 2023, 'MARS': 'single', 'value': 1800.0},
         {'year': 2023, 'MARS': 'mjoint', 'value': 1500.0},