Alaska Form 6390 – Federal-Based Credits
Last reviewed: 2025-11-12
Use the Alaska Tax Form Calculator Form 6390: Alaska Form 6390 – Federal-Based Credits as a stand alone tax form calculator to quickly calculate specific amounts for your 2026 Alaska state tax return. Alternatively, you can use one of our Combined Federal and State Tax Estimators to quickly calculate your salary, tax, and take-home pay.
Alaska Form 6390 is used by corporations to compute Alaska’s allowable portion of federal-based business credits. Although these credits originate at the federal level—primarily via the general business credit system (Form 3800)—Alaska applies its own allocation, apportionment and limitation rules. Form 6390 consolidates these requirements into a structured multi-part calculation that determines how much of the federally generated credit can reduce a corporation’s Alaska income tax liability.
The form accounts for credit types that behave differently under Alaska law, including passive-activity credits, investment credits not allowed for Alaska AMT, credits flowing through from partnerships or S corporations and credits that exceed the current-year limitation. By integrating both the regular Alaska tax and the Alaska alternative minimum tax (AMT), Form 6390 ensures that corporations adopt the correct multi-layered credit restrictions before applying offsets to their return (Forms 6000, 6100 or 6150).
This calculator replicates all computational lines, allowing businesses to evaluate available credits, allowable credit limits and the amount eligible for carryback or carryforward. It is especially useful for multi-state corporations that must apply Alaska’s apportionment factor to determine the state-specific share of federal credits.
How Alaska Form 6390 Works
The structure of the form divides the credit computation into segments that progressively refine the allowable amount. The major components are:
- Identify federal-based credits: Enter general business credits from federal Form 3800, separating passive-activity and non-passive-activity amounts. These amounts then undergo Alaska-specific disallowance adjustments.
- Apply Alaska apportionment: Alaska requires all federal-based credit amounts to be multiplied by the corporation’s Alaska apportionment factor, ensuring that only Alaska-sourced business activity impacts the credit determination.
- Compute AMT interactions: Alaska distinguishes credits available against regular tax and those that also apply to Alaska AMT. The form walks through these calculations to establish both totals.
- Calculate tax limitations: The form uses several limitation tests, including a threshold for reducing credits when Alaska regular tax exceeds $4,500. These limitations prevent credits from reducing tax below permitted levels.
- Determine allowable credit and carryover: The form concludes with the credit allowed for the current year and the remaining amount eligible for carryback or carryforward. These figures feed directly into Form 6000, 6100 or 6150.
Corporations with complex federal-credit structures, such as energy credits, rehabilitation credits or investment credits, rely on Form 6390 to ensure Alaska-specific compliance. The calculator automates all arithmetic steps while still following the exact line-by-line layout of the official form.
| PART I — Current Year Credit for Credits Not Allowed Against Alaska AMT | ||
| 1 | Federal general business credit from non-passive activity (Form 3800, Part III line 2e) | |
| 2a | Federal investment credit from non-passive activity not allowable for Alaska | |
| 2b | Other federal general business credits not allowable for Alaska | |
| 2c | Add lines 2a–2b | |
| 3 | Line 1 minus line 2c (Credits applicable to Alaska) | |
| 4 | Applicable general business credit from passive activity (Form 6395 line 17) | |
| 5 | Add lines 3 and 4 | |
| 6 | Apportionment factor | |
| 7 | Line 5 × line 6 | |
| 8 | Total apportioned general business credit (Multiply line 7 by 0.18) | |
| 9 | Alaska carryforward of general business credit | |
| 10 | Alaska carryback of general business credit | |
| PART II — Allowable Credit | ||
| 12a | Alaska regular tax (Form 6000/6100/6150 Schedule D line 2) | |
| 12b | Alaska incentive credits allowed against regular tax | |
| 12c | Line 12a minus line 12b (not less than zero) | |
| 13a | Net Alaska alternative minimum tax | |
| 13b | Alaska incentive credits against AMT | |
| 13c | Line 13a minus line 13b (not less than zero) | |
| 14 | Net Alaska income tax (add lines 12c and 13c) | |
| 15 | 25% of excess of line 12c over $4,500 | |
| PART IV — Tax Limitation | ||
| 29a | Net Alaska income tax (enter amount from line 14) | |
| 29b | Enter amount from line 15 | |
| 29c | Line 29a minus line 29b (not less than zero) | |
| 30 | Enter amount from line 17 | |
| 31 | Limitation: line 29c minus line 30 | |
| 32 | Smaller of line 28 or line 31 | |
| 33 | Credit allowed for the current year (Add lines 17 and 32; enter on Form 6000/6100/6150 Schedule A line 8) | |
Understanding Alaska’s Approach to Federal-Based Credits
Alaska is one of the few states that does not impose an individual income tax but maintains a detailed and sophisticated corporate income tax system. Federal-based business credits play an important role in this structure, especially for companies engaged in resource development, manufacturing, transportation, engineering and other capital-intensive sectors.
Form 6390 ensures consistency and prevents over-claiming of credits by aligning Alaska’s tax framework with federal credit limitations while also adjusting for Alaska-only considerations such as AMT treatment and apportionment. This prevents distortion where a corporation might generate federal credits unrelated to Alaska operations and then apply them disproportionately to reduce Alaska tax liability.
Businesses operating multiple facilities across states—common in oil & gas, shipping, logistics and construction—benefit greatly from correctly applying the apportionment factor. Errors in this area can result in significant underpayments or the loss of legitimate credit opportunities. Proper use of Form 6390 helps maintain conformity with the Alaska Department of Revenue’s requirements and ensures defensible tax reporting.
Last reviewed: 2025-11-12: If you believe this form requires an update, please contact us.
Additional Resources
- Federal Form 1120 Calculator
- Federal Form 3800 Calculator
- Alaska Form 6000 – Corporation Net Income Tax Return
- Alaska Form 6100 – S Corporation Return
- Alaska Form 6150 – Oil & Gas Corporation Tax Return
Corporations using federal general business credits should review Form 6390 annually, especially when tax liability, credit types or apportionment factors change. The calculator ensures a precise and compliant Alaska-specific computation of allowable credits and carryover amounts.
Quick Access Tools
Frequently Asked Questions
Are Alaska unemployment taxes included?
Employer-paid unemployment contributions exist in Alaska, but employees do not have unemployment tax withheld from their paycheck. Alaska operates a unique unemployment insurance system where both the employer and employee may contribute depending on current rate schedules, but employee deductions—if required for a given year—are typically small. Some years the employee rate is 0%. These contributions are not income taxes and do not affect your federal taxable wages.
How can I model long-term savings growth due to Alaska’s 0% income tax?
Because Alaska does not reduce your paycheck through wage-based taxes, the money you save can be invested or contributed to retirement accounts to compound over time. Tools like the Compound Interest Calculator and CAGR Calculator let you project how much faster savings grow when you retain more of your income. Even a modest annual investment of your “tax savings” can build significant wealth due to compounding over many years.
Are there any Alaska-specific rules for claiming dependents on my federal return?
No. Alaska does not maintain a state tax system, so it does not impose additional dependency tests, household requirements, documentation layers, or residency proofs. All federal dependency rules apply normally, including support tests, relationship tests, residency requirements and income limits. The lack of state-level additions makes dependency filing simpler for Alaska households than in most states.
Where can I access the reference page or tool for Form 6100?
A complete overview of the form, instructions and structured calculator logic is available at Alaska Form 6100 Calculator. This provides item-by-item explanations, relevant schedules and state-level guidance for S corporations.
Are there any Alaska state withholdings?
No standard payroll withholdings exist because Alaska does not impose a personal income tax. Employers do not submit state withholding accounts, state returns, or state payroll forms similar to W-4. The only exceptions relate to employer-funded programs such as unemployment insurance, but these do not appear as employee deductions on your paycheck. In most cases your wage slip will include only federal withholding, FICA, Medicare, and any voluntary deductions like health insurance or retirement contributions.
Important Notes
All calculations are estimates for guidance only. Always review your return and consider professional advice when submitting official filings.