When Congress passed the One Big Beautiful Bill Act (OBBBA), many businesses welcomed the return of more favorable treatment for domestic research and experimental (R&E) expenditures. At the federal level, the changes largely moved the conversation from capitalization back toward immediate deductions.
But as state and local tax (SALT) professionals know, federal tax changes are rarely the end of the story.
For corporate excise tax purposes, Massachusetts has temporarily stepped away from the new federal rules, creating another example of how state conformity decisions can quickly turn a federal tax benefit into a multistate compliance exercise.
Massachusetts Takes a Different Path
While generally following “rolling conformity” for corporate excise and automatically adopting federal tax law changes, Massachusetts has chosen to slow the impact of several of these changes for the 2025 tax year.
Specific to R&E expenditures, the laws disallows several federal provisions under the OBBBA including the ability to immediately deduct domestic R&E expenditures through new IRC §174A; the ability for qualifying small businesses to retroactively deduct domestic R&E expenditures for tax years beginning after December 31, 2021; and it disallows a deduction of the remaining unamortized balance of previously capitalized expenses.
The state is requiring taxpayers to calculate their Massachusetts deduction using the version of IRC §174 that existed before the federal changes took effect. In other words, a deduction that may be available federally could be treated very differently for Massachusetts purposes.
The state’s decoupling is temporary with the disallowance provisions being repealed for tax years beginning on or after January 1, 2026, but for 2025 it creates a clear disconnect between federal and Massachusetts taxable income.
The Real Challenge Isn’t the Federal Rule
The federal treatment itself is relatively straightforward. The bigger issue is that businesses now need to track two (or more) separate calculations for the same R&E expenditure.
A company that takes advantage of the federal §174A deduction will find that Massachusetts requires a completely different computation, resulting in state adjustments and potentially higher Massachusetts taxable income. This treatment may also vary across other states in which the company transacts business.
For SALT practitioners, the real challenge lies in navigating how individual states respond to federal tax changes and where they choose to diverge.
What If You Already Filed?
For some taxpayers, the timing adds another layer of complexity.
Massachusetts enacted these changes after some businesses had already filed returns based on the federal tax treatment. Recognizing that situation, the legislation includes penalty and interest relief for certain taxpayers who amend their returns prior to September 10th to reflect the new Massachusetts rules.
That’s welcome news, but it doesn’t eliminate the need to revisit prior filings and evaluate whether additional tax may be due.
A Practical Next Step
Affected taxpayers should consider taking a fresh look at their Massachusetts filings and:
- Recalculate Massachusetts taxable income without the federal §174A deduction.
- Determine the R&E deduction allowed under Massachusetts’ version of §174.
- Assess whether amended returns are needed at the entity or owner level.
- Calculate any additional Massachusetts tax liability.
- Document eligibility for available penalty and interest relief.
For businesses operating in multiple states, this review may uncover additional state-specific adjustments as other jurisdictions continue to adopt their own conformity approaches.
A Growing State Conformity Trend
Massachusetts is hardly alone. Several states have modified or decoupled from portions of the federal R&E changes, including Minnesota, Rhode Island, and New York.
As states evaluate the revenue impact of accelerated deductions and retroactive elections, we’re seeing more variation in how federal tax changes are implemented at the state level. That means taxpayers can no longer assume a federal deduction will automatically flow through to every state return.
Adding to the complexity, retroactive elections, transition deductions, and R&D credit coordination rules can all create separate state adjustments that need to be tracked carefully.
The Bottom Line
The Massachusetts §174A decoupling is a good reminder that tax reform doesn’t always move in a straight line.
While federal law may have simplified the treatment of domestic R&E expenditures, Massachusetts has created a temporary state-federal mismatch that taxpayers cannot afford to overlook. Businesses that have already filed, or plan to file in the near future, should evaluate how the state’s temporary decoupling affects their returns and whether corrective action is needed.
If you have any questions or are interested in learning more, we are here to help. Please do not hesitate to reach out to discuss your specific situation.
This material has been prepared for general, informational purposes only and is not intended to provide, and should not be relied on for, tax, legal or accounting advice. Should you require any such advice, please contact us directly. The information contained herein does not create, and your review or use of the information does not constitute, an accountant-client relationship.
