The alternative simplified credit (ASC) is one of the two methods for computing the federal R&D tax credit under Section 41 of the Internal Revenue Code. This page explains the current statutory formula, the inputs needed, and a worked example. It is educational and is not individualized tax advice. For the calculation overview, see our page on how the R&D tax credit is calculated.
The ASC Formula
Under Section 41(c)(4), the ASC is computed as follows:
If the taxpayer has QREs in all three of the preceding taxable years:
ASC = 14% × (current-year QREs − 50% × average QREs for the 3 preceding years)
If the taxpayer has no QREs in any one of the three preceding taxable years:
ASC = 6% × current-year QREs
The "average QREs for the 3 preceding years" is the sum of QREs for the three taxable years preceding the credit year, divided by three. For more on the no-prior-QRE rule, see our page on R&D credit with no prior QREs, and for the prior-three-year mechanics, see our page on prior three years of QREs.
Why the ASC Exists
The ASC was introduced as a simpler alternative to the regular credit method. It does not require gross-receipts data or a fixed-base percentage based on 1984–1988 historical information. Instead, it relies on the taxpayer's own prior three years of QRE history. This can make the ASC more practical for companies that do not have the historical gross-receipts and research-spending data the regular method requires.
Inputs Needed
To compute the ASC, the following inputs are needed:
- Current-year QREs. The qualified research expenses for the credit year — certain wages, certain supplies, and 65% of certain contract research costs. For more, see our page on qualified research expenses.
- Prior three years of QREs. The QREs for each of the three taxable years preceding the credit year. These must be supportable by prior-year records. For more, see our page on how QREs feed the calculation.
A Clearly Labeled Worked Example
The following is a hypothetical illustration for educational purposes only. It does not represent any actual taxpayer and does not state a filing recommendation.
Suppose a company has the following QRE history:
| Period | QREs | |---|---| | 3 years preceding (Year 1) | $300,000 | | 3 years preceding (Year 2) | $350,000 | | 3 years preceding (Year 3) | $400,000 | | Current year | $500,000 |
Step 1: Compute the prior 3-year average.
Average = ($300,000 + $350,000 + $400,000) / 3 = $1,050,000 / 3 = $350,000
Step 2: Compute 50% of the average.
50% × $350,000 = $175,000
Step 3: Compute the excess.
Excess = $500,000 − $175,000 = $325,000
Step 4: Apply the 14% rate.
ASC = 14% × $325,000 = $45,500
The tentative ASC for the current year is $45,500. This is the gross credit before any elections or limitations — it is not necessarily the amount of tax the taxpayer will actually reduce. For the distinction, see our page on whether the R&D credit reduces taxes owed.
What Happens If an Input Is Zero or Unavailable
- If prior QREs are zero in any one of the three years. The 6% special rule under Section 41(c)(4)(B) applies: ASC = 6% × current QREs. The zero-QRE year is not included in the average — the 6% rate is applied directly to current-year QREs. For more, see our page on no prior QREs.
- If prior-year QRE records are missing. Missing documentation is not the same as zero QREs. Taxpayers should not assume that missing records mean zero QREs. The prior QREs must be supportable.
Common Misunderstanding
A common misunderstanding is that the ASC is simply 14% of all current R&D spending. It is not. The 14% rate applies only to the excess of current QREs over 50% of the prior three-year average. If current QREs are not significantly higher than the prior average, the excess — and therefore the credit — may be small. Conversely, if current QREs are much higher than the prior average, the credit may be larger.
Relationship to Form 6765
The ASC is computed on Section B of Form 6765. The current form (12/2025 revision) requests current-year QREs, prior-year QREs, the average, and the resulting credit. For a line-by-line conceptual walkthrough, see our page on Form 6765 ASC calculation.
Documentation Needed to Support the Numbers
The ASC depends on both current-year and prior-year QREs. Records that may help include payroll records with qualified-service allocations, contractor agreements and payments, supply records, project records, and prior-year QRE workpapers. The prior-year QREs must be supportable — not estimated or assumed. For more, see our page on R&D tax credit documentation.
Questions for Your Tax Professional
- Do I have supportable prior-year QRE records for the three preceding years?
- Does the 6% special rule (no QREs in any one of the 3 preceding years) apply to me?
- How does the ASC compare to the regular method for my facts?
- Are my current-year QREs properly allocated and documented?
- What elections and limitations may affect the usable credit?
Key Takeaway
The ASC is generally 14% of current-year QREs that exceed 50% of the average QREs for the three preceding taxable years, or 6% of current-year QREs if the taxpayer has no QREs in any one of the three preceding years. The ASC does not require gross-receipts data, but it does require supportable prior-year QRE records. The 14% rate applies to an excess, not to all current R&D spending. Because the calculation depends on specific facts, professional tax review is appropriate. For the regular method comparison, see our page on ASC vs. regular.