18% Limitation

Defining the Alaska R&D Credit Limitation

The Alaska R&D tax credit is a mechanism designed to adopt the federal credit while limiting its fiscal impact on the state. Alaska does not offer its own state-specific R&D tax credit based on qualified expenses; instead, it adopts the federal R&D tax credit (IRC § 41). The 18% Limitation mandates that the resulting Alaska credit for corporations cannot exceed 18% of the federal credit amount that is properly attributed or apportioned to Alaska business activity.

Alaska’s framework for corporate tax incentives relies heavily on leveraging the federal Internal Revenue Code (IRC). Alaska Statute (AS) 43.20.021 adopts key sections of the IRC (Sections 1–1399 and 6001–7872) by reference, granting them “full force and effect,” subject only to modifications defined by Alaska law. The 18% rule functions as the primary state modification impacting federal-based tax credits, including the Research and Experimentation Tax Credit (IRC § 41).

This adoption mechanism means that the definition of qualified research expenses (QREs) and qualified research activities (QRA) in Alaska is identical to the Federal Four-Part Test, which requires activities to be technological in nature, performed for a permitted purpose, and aimed at eliminating uncertainty. Consequently, the state credit’s value is permanently tethered to the underlying federal tax determination. If the federal credit base is altered—for example, by changes in federal capitalization or amortization rules—this change automatically impacts the starting point for the state calculation, creating a pathway for regulatory volatility driven entirely by federal policy, despite the fixed 18% rate in Alaska law.

Crucially, for multi-state entities, the 18% limitation is actually a composite of two scaling factors. It requires the federal credit to be first scaled down by the taxpayer’s corporate apportionment factor, which localizes the credit to Alaska business activity. Only then is the 18% rate applied to the resulting apportioned figure. This credit, once calculated, provides a direct, dollar-for-dollar offset against Alaska corporate net income tax liabilities.

Statutory and Regulatory Foundations of the 18% Rule

The legal authority for the credit limitation is precisely defined within Alaska’s tax statutes and administrative code.

The Legislative Mandate: Alaska Statute 43.20.021(d)

AS 43.20.021, which governs the state’s adoption of the IRC, contains the definitive legal language in subsection (d). This statute explicitly states: “Where a credit allowed under the Internal Revenue Code is also allowed in computing Alaska income tax, it is limited to 18 percent for corporations of the amount of credit determined for federal income tax purposes which is attributable to Alaska”.

This language establishes two non-negotiable prerequisites for claiming the Alaska credit: the credit must be allowable under IRC § 38 (which includes the R&D credit under IRC § 41), and it must be properly attributable to Alaska. This structure subjects the R&D credit to the 18% cap. It is noted that this specific limitation does not apply to a special industrial incentive tax credit under AS 43.20.042, indicating a specific legislative carve-out designed to preserve the full benefit of certain state-driven performance incentives.

Administrative and Regulatory Context

The Alaska Administrative Code provides regulatory context for implementation. 15 AAC 20.145 confirms the administrative adoption of the federal credits and their subsequent limitation. The regulation further clarifies that the federal credit, when allowed for Alaska computation, is subject to the 18% limitation and the necessary apportionment.

The Department of Revenue (DOR) further notes that while most of the IRC is adopted, certain sections, specifically Internal Revenue Code Sections 1400–1400U, are not adopted by Alaska. While this exclusion does not affect the core R&D credit under IRC § 41, it necessitates careful review by taxpayers claiming any other adopted federal-based credits.

The consistency across the statute and the administrative code emphasizes the mandatory nature of the dual calculation process, ensuring that the final credit amount is appropriately scaled based on the taxpayer’s economic presence in Alaska before the rate limitation is applied.

The Alaska Research and Development Tax Credit Calculation Framework

The calculation of the Alaska R&D credit involves a mandatory three-step process for multi-state entities, dictated by the requirement to determine the portion of the federal credit that is “attributable to Alaska.”

Step One: Determining the Base Federal Credit (IRC § 38)

The foundation of the Alaska credit is the accurately calculated federal R&D tax credit. Taxpayers must first determine the total federal General Business Credit (GBC) under IRC § 38, of which the R&D credit (calculated on Federal Form 6765) is a primary component. The definition of qualified research expenses (QREs) is strictly based on IRC § 41, and activities must be conducted within the United States, although they need not be located physically within Alaska to contribute to the overall federal base.

Step Two: Apportionment—Scaling the Credit Base

This is the most crucial compliance step for any multi-state corporation. The taxpayer must use the same Alaska corporate income tax apportionment factor that is calculated for their state return to determine the percentage of the total federal credit attributable to Alaska.

Apportionment Methodology

Alaska’s apportionment laws dictate how the business activity of multi-state corporations is measured. Alaska traditionally used an equally weighted three-factor apportionment formula, consisting of property, payroll, and sales.

However, the state has modernized its apportionment rules, particularly for the digital economy. Legislation has introduced market-based sourcing and adopted a single sales factor (SSF) for specific highly digitized businesses. This shift in methodology directly impacts the R&D credit calculation. R&D-heavy corporations often maintain high payroll and property factors (engineers, labs) within the state. If such a corporation switches to an SSF rule and its sales are predominantly outside Alaska, its overall apportionment factor will decrease. This reduction in the apportionment factor directly shrinks the credit base (the “amount attributable to Alaska”), leading to a smaller potential R&D tax benefit, even if the research activities themselves remain stable in the state. Taxpayers must ensure they are using the legally required apportionment methodology to calculate the most accurate credit base.

Step Three: Applying the 18% Limitation

Once the federal credit has been scaled by the Alaska Apportionment Factor, the statutory 18% limitation is applied to the resulting figure. This final multiplication yields the maximum allowed Alaska R&D credit.

It is imperative that the apportionment factor be applied before the 18% rate. The statute makes it clear that the 18% limit applies to the credit amount “which is attributable to Alaska”. Applying the 18% rate to the full federal credit before apportionment is a common error that significantly overstates the eligible state benefit and poses a high risk of audit deficiency.

The calculation workflow adheres to the following logic:

Alaska R&D Credit = (Federal Credit x Alaska Apportionment Factor) x 0.18

State Revenue Office Guidance and Compliance Requirements

The Alaska Department of Revenue (DOR) mandates compliance through specific forms and governs the strategic use of the resulting credit through strict ordering rules.

Alaska Form 6390 and Required Documentation

To claim the limited federal-based credit, corporations must file Alaska Form 6390 – Alaska Federal-based Credits along with their state income tax return (Form 6000, 6100, or 6150). The instructions for Form 6390 confirm that its purpose is to “order and limit federal-based credits, on an as-if Alaska basis”.

The DOR’s guidance within the Form 6390 instructions explicitly requires the two-step limitation: the credit is limited to 18% of the federal amount, “and apportioned, if applicable”. Compliance requires the taxpayer to supply the necessary underlying documentation, which includes data derived directly from the Federal Form 6765 (Research Credit) or Federal Form 3800 (General Business Credit). Because Alaska’s claim rests entirely on the federal determination, any adjustment made by the IRS to the underlying Federal Form 6765 calculation automatically necessitates an amended Alaska return and a recalculation of the 18% limited amount.

Credit Utilization and Carryover Rules

The longevity and usability of the Alaska R&D credit are significant features that enhance its strategic value.

Carryover Period

Unused federal-based credits, including the R&D credit, have a long carryover period. They may be carried back for one year and forward for up to 20 years. This robust, 20-year carryforward mirrors the federal provision and provides essential stability for companies engaged in long-term R&D, ensuring that the benefit is not lost during years of net operating losses or low tax liability.

Alternative Minimum Tax (AMT) Offset Rules

The credit may be used to offset Alaska Alternative Minimum Tax (AMT). However, strict ordering rules apply: Federal-based credits may offset Alaska AMT only after all Alaska incentive credits have been applied. This established hierarchy prioritizes state-specific, locally crafted incentives over federal benefits adopted by reference.

From a strategic perspective, this rule encourages taxpayers to maximize the use of any shorter-lived or non-carryover state incentive credits first, thereby preserving the highly valuable, 20-year federal-based R&D credit for use in later, potentially higher-tax years.

Practical Application: A Multi-State R&D Tax Credit Case Study

This case study demonstrates the compulsory application of the apportionment factor before the 18% limitation.

Scenario: Aurora Tech Innovations

Aurora Tech Innovations (ATI), a C-Corporation, designs and manufactures components for the oil and gas industry and operates across multiple states, including Alaska.

Metric	Input/Factor
Total U.S. Qualified Research Expenses (QREs)	$900,000
Calculated Federal R&D Credit (IRC § 41, Step 1)	$90,000
Alaska Apportionment Factor (AF) (Step 2)	18% (0.18)
Alaska Statutory Limitation Rate (Step 4)	18% (0.18)

Detailed Calculation Workflow

The calculation adheres strictly to the requirement set forth in AS 43.20.021(d).

1. Determine Federal Base Credit (Step 1)

ATI calculates its total federal R&D credit for the year: $90,000.

2. Apportion Federal Credit to Alaska Sources (Step 3)

The Federal Credit must be scaled down by the Alaska Apportionment Factor (AF = 18%) to reflect the portion of business activity attributed to Alaska.

Attributable Federal Credit = $90,000 x 0.18 = $16,200

The result, $16,200, is the localized credit base amount.

3. Apply the Alaska 18% Limitation (Step 4)

The final statutory rate is applied only to the attributable amount.

Final Alaska R&D Tax Credit = $16,200 x 0.18 = $2,916

The maximum allowable Alaska R&D tax credit that ATI can claim on Form 6390 is $2,916.

Significance of the Dual Limitation

If ATI were to calculate the credit by applying the 18% limit only to the full federal credit of $90,000, the claimed amount would be $16,200 (as demonstrated in prior year examples), which significantly exceeds the legally allowed value of $2,916.

The primary factor driving the low final credit value is the low apportionment factor (18%), which suggests that a majority of ATI’s corporate activity is allocated outside of Alaska. If, for instance, ATI was subject to the state’s new single sales factor (SSF) methodology, and its sales factor was determined to be even lower than 18%, the resulting credit would be further compressed. Understanding the nuances of the corporate apportionment method—whether the three-factor or the SSF applies—is therefore a critical prerequisite for accurate calculation, often carrying a greater financial impact than the fixed 18% limitation itself.

Final Thoughts and Strategic Considerations for Taxpayers

The Alaska R&D tax credit is a straightforward but restrictive incentive. The 18% limitation, codified in AS 43.20.021(d), functions as the final ceiling, applied only after the prerequisite step of apportioning the underlying federal credit to Alaska business sources is complete. This dual limitation ensures that the credit benefit is proportional to the corporate activity taxed by the state.

While the 18% rate is comparatively low against other states that may offer credits equal to a higher percentage of the federal amount or a percentage of QREs, the Alaska credit offers significant benefits in terms of stability and longevity. Because the state entirely adopts the federal calculation methodology, the administrative burden of preparing a separate state-specific R&D study is eliminated.

For corporate tax departments, the strategic value of the Alaska R&D credit lies not in its magnitude but in its utility. The generous 20-year carryforward period provides a valuable, persistent asset capable of offsetting future tax liabilities over two decades. Furthermore, adherence to the specific credit ordering rules—using local Alaska incentives before federal-based credits against the Alternative Minimum Tax—allows corporations to efficiently manage their credit portfolio, preserving the long-lived R&D credit for optimal utilization. Accurate compliance requires not just knowing the 18% rate, but correctly applying the corporate apportionment factor as determined by current Alaska law and utilizing Form 6390 to calculate and claim the benefit.