A common question is the difference between software bug fixes and qualified research for the R&D tax credit. The short answer is that routine bug fixes that apply known fixes to known problems generally are not qualified research. Bug investigation that involves an uncertain technical problem and a process of experimentation may warrant review. This page explains the framework in general terms. It is educational and is not individualized advice. For the foundational framework, see our page on qualified research.
Routine Bug Fixes
Routine bug fixes — diagnosing a known bug with a known cause and applying a known fix — generally are not qualified research. The characteristics of routine bug fixes include:
- Known bug — the bug is familiar and has been seen before.
- Known cause — the cause of the bug is established.
- Known fix — the fix is established and is applied routinely.
Where all three are present, the work is applying established knowledge, not conducting research. The elimination of uncertainty and process of experimentation elements are generally not satisfied.
Bug Investigation That May Warrant Review
Bug investigation may warrant review when it involves an uncertain technical problem and a process of experimentation:
- Uncertain bug — the bug is new or unfamiliar, and the cause is not established.
- Uncertain cause — the root cause is uncertain, and alternative hypotheses need to be evaluated.
- Uncertain fix — the fix is not established, and alternative corrective approaches need to be tested.
Where the investigation involves evaluating alternative root-cause hypotheses and testing corrective approaches through a structured process, the work may warrant review as qualified research. For more on this distinction, see our page on troubleshooting vs. R&D.
The Distinction Is in the Uncertainty
The distinction between routine bug fixes and qualified research is in the uncertainty:
- Routine bug fix — known bug, known cause, known fix. No technical uncertainty. Not qualified research.
- Bug investigation as research — uncertain bug, uncertain cause, uncertain fix. Technical uncertainty present, and a process of experimentation to evaluate alternatives. May warrant review.
The same physical activity — debugging code — can be routine bug fixing or research depending on whether there is a genuine technical uncertainty and a process of experimentation.
Hypothetical Example
Consider a company that experiences a new, unfamiliar bug in a new system and is uncertain of the cause. The company evaluates alternative root-cause hypotheses, tests each, and develops a corrective approach through a structured process. This investigation of an uncertain problem and evaluation of corrective alternatives may warrant review as qualified research.
By contrast, if the company fixes a known null-pointer bug by applying a standard null check, that is a routine bug fix, not research.
These examples are illustrative only and do not state whether any particular activity qualifies.
Documentation That May Help
Records that can help support bug investigation claims include records showing whether the bug, cause, and fix were known or uncertain, records of alternative hypotheses evaluated, and records of the process of experimentation. For more, see our page on R&D tax credit documentation.
Key Takeaway
Routine bug fixes that apply known fixes to known problems generally are not qualified research. Bug investigation that involves an uncertain technical problem and a process of experimentation may warrant review. Because the distinction is fact-specific, professional review is appropriate before claiming the credit.