Subchapter A. Determination of Tax Liability

Part I TAX ON INDIVIDUALS §§ 1–5

1. § 1 Tax imposed
2. § 2 Definitions and special rules
3. § 3 Tax tables for individuals
4. § 4 Repealed
5. § 5 Cross references relating to tax on individuals

Part II TAX ON CORPORATIONS §§ 11–12

1. § 11 Tax imposed
2. § 12 Cross references relating to tax on corporations

Part III CHANGES IN RATES DURING A TAXABLE YEAR § 15

1. § 15 Effect of changes

Part IV CREDITS AGAINST TAX §§ 21–54AA

1. Subpart A Nonrefundable Personal Credits §§ 21–26

   1. § 21 Expenses for household and dependent care services necessary for gainful employment
   2. § 22 Credit for the elderly and the permanently and totally disabled
   3. § 23 Adoption expenses
   4. § 24 Child tax credit
   5. § 25 Interest on certain home mortgages
   6. § 25A American Opportunity and Lifetime Learning credits
   7. § 25B Elective deferrals and IRA contributions by certain individuals
   8. § 25C Energy efficient home improvement credit
   9. § 25D Residential clean energy credit
   10. § 25E Previously-owned clean vehicles
   11. § 25F Qualified elementary and secondary education scholarships
   12. § 26 Limitation based on tax liability; definition of tax liability

2. Subpart B Other Credits §§ 27–30D

   1. § 27 Taxes of foreign countries and possessions of the United States
   2. § 28 Renumbered
   3. § 29 Renumbered
   4. § 30 Repealed
   5. § 30A Repealed
   6. § 30B Alternative motor vehicle credit
   7. § 30C Alternative fuel vehicle refueling property credit
   8. § 30D Clean vehicle credit

3. Subpart C Refundable Credits §§ 31–37

   1. § 31 Tax withheld on wages
   2. § 32 Earned income
   3. § 33 Tax withheld at source on nonresident aliens and foreign corporations
   4. § 34 Certain uses of gasoline and special fuels
   5. § 35 Health insurance costs of eligible individuals
   6. § 36 First-time homebuyer credit
   7. § 36A Repealed
   8. § 36B Refundable credit for coverage under a qualified health plan
   9. § 36C Renumbered
   10. § 37 Overpayments of tax

4. Subpart D Business Related Credits §§ 38–45AA

   1. § 38 General business credit
   2. § 39 Carryback and carryforward of unused credits
   3. § 40 Alcohol, etc., used as fuel
   4. § 40A Biodiesel and renewable diesel used as fuel
   5. § 40B Sustainable aviation fuel credit
   6. § 41 Credit for increasing research activities
   7. § 42 Low-income housing credit
   8. § 43 Enhanced oil recovery credit
   9. § 44 Expenditures to provide access to disabled individuals
   10. § 44A Renumbered
   11. § 44B Repealed
   12. § 44C Renumbered
   13. § 44D Renumbered
   14. § 44E Renumbered
   15. § 44F Renumbered
   16. § 44G Renumbered
   17. § 44H Renumbered
   18. § 45 Electricity produced from certain renewable resources, etc.
   19. § 45A Indian employment credit
   20. § 45B Credit for portion of employer social security taxes paid with respect to employee cash tips
   21. § 45C Clinical testing expenses for certain drugs for rare diseases or conditions
   22. § 45D New markets tax credit
   23. § 45E Small employer pension plan startup costs
   24. § 45F Employer-provided child care credit
   25. § 45G Railroad track maintenance credit
   26. § 45H Credit for production of low sulfur diesel fuel
   27. § 45I Credit for producing oil and gas from marginal wells
   28. § 45J Credit for production from advanced nuclear power facilities
   29. § 45K Credit for producing fuel from a nonconventional source
   30. § 45L New energy efficient home credit
   31. § 45M Repealed
   32. § 45N Mine rescue team training credit
   33. § 45O Agricultural chemicals security credit
   34. § 45P Employer wage credit for employees who are active duty members of the uniformed services
   35. § 45Q Credit for carbon oxide sequestration
   36. § 45R Employee health insurance expenses of small employers
   37. § 45S Employer credit for paid family and medical leave
   38. § 45T Auto-enrollment option for retirement savings options provided by small employers
   39. § 45U Zero-emission nuclear power production credit
   40. § 45V Credit for production of clean hydrogen
   41. § 45W Credit for qualified commercial clean vehicles
   42. § 45X Advanced manufacturing production credit
   43. § 45Y Clean electricity production credit
   44. § 45Z Clean fuel production credit
   45. § 45AA Military spouse retirement plan eligibility credit for small employers

5. Subpart E Rules for Computing Investment Credit §§ 46–50A, 50B

   1. § 46 Amount of credit
   2. § 47 Rehabilitation credit
   3. § 48 Energy credit
   4. § 48A Qualifying advanced coal project credit
   5. § 48B Qualifying gasification project credit
   6. § 48C Qualifying advanced energy project credit
   7. § 48D Advanced manufacturing investment credit
   8. § 48E Clean electricity investment credit
   9. § 49 At-risk rules
   10. § 50 Other special rules
   11. § 50A, 50B Repealed

6. Subpart F Rules for Computing Work Opportunity Credit §§ 51–52

   1. § 51 Amount of credit
   2. § 51A Repealed
   3. § 52 Special rules

7. Subpart G Credit Against Regular Tax for Prior Year Minimum Tax Liability § 53

   1. § 53 Credit for prior year minimum tax liability

8. Subpart H Repealed § 54

   1. § 54 Repealed

9. Subpart I Repealed § 54A–54F

   1. § 54A–54F Repealed

10. Subpart J Repealed § 54AA

    1. § 54AA Repealed

Part V REPEALED

Part VI ALTERNATIVE MINIMUM TAX §§ 55–59

1. § 55 Alternative minimum tax imposed
2. § 56 Adjustments in computing alternative minimum taxable income
3. § 56A Adjusted financial statement income
4. § 57 Items of tax preference
5. § 58 Denial of certain losses
6. § 59 Other definitions and special rules

Part VII BASE EROSION AND ANTI-ABUSE TAX § 59A

1. § 59A Tax on base erosion payments of taxpayers with substantial gross receipts

Part VIII REPEALED § 59B

1. § 59B Repealed