Defined term
Four-part test
Also: §41 four-part test
The U.S. eligibility test for qualified research under Section 41.
To qualify under U.S. federal rules, an activity must generally meet four requirements: a permitted purpose (new or improved business component), technological in nature (reliance on principles of the physical or biological sciences, engineering, or computer science), elimination of technological uncertainty, and a process of experimentation. Failure on any element can remove related expenses from the credit base. Documentation should map facts to each element.
Related on the Index
Related terms
Common questions
- Does passing the four-part test automatically mean every related cost is a QRE?
- No. Activities may qualify while some cost categories still fail statutory inclusions, exclusions, or nexus rules. Expense analysis remains a separate step.
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Educational definition only. Not tax or legal advice. Confirm current program rules with official guidance and a qualified adviser.