Connecticut R&D credit rules for TY2026
Each row is a field from the registry entry our engine applies. A blank field says so; it is never filled in.
Program flags on this entry
- Stacked tiered 217n
- Yes
- Credit for TY2026
- Current credit Yes. Our rules registry carries a current Connecticut research credit for tax year 2026.
- Structure
- Incremental: the credit applies to qualified research expenses above a state base amount
- Credit rate
- 20% of qualified research expenses above the base amount
- Base method
- The base amount is the average Connecticut qualified research expenses of the 1 preceding year. Where a prior year is missing from the data, the engine flags the substitute base it used rather than quietly assuming one.
- Liability limit
- 70% of the applicable tax liability Tax liability sits outside the study, so this is a preparer determination at filing time, not something the study computes.
- Carryforward
- 15 years
- Carryback
- None recorded
- Refundable?
- Not determined in our registry - we confirm it in the study The registry treats an unverified "nonrefundable" as unknown rather than asserting it.
- State form
- CT-1120 RDC / CT-1120 RC
- Statute
- Conn. Gen. Stat. §12-217j (20% incremental); §12-217n (tiered non-incremental)
How the Connecticut credit is computed
The Connecticut credit is incremental: it applies to the qualified research expenses that exceed a state base amount, not to the whole year's spending. The registry carries a rate of 20%.
The base amount is the average Connecticut qualified research expenses of the 1 preceding year. Where a prior year is missing from the data, the engine flags the substitute base it used rather than quietly assuming one.
On limits, the amount used in a year is limited to 70% of the applicable tax liability. Unused credit carries forward 15 years. Refundability: not determined in our registry, so the study confirms it against the statute rather than asserting it here.
Ricerca computes the Connecticut figure from the same substantiated expenses as the federal §41 credit, under the registry entry for the year claimed. Where the registry is silent, the study says so and the point is resolved with your return preparer, not assumed.
Claiming it alongside the federal credit
The federal §41 credit comes first: it is computed from the qualified research expenses the study substantiates and filed on Form 6765 with the return. The Connecticut credit is then computed from that same base under the state's own rules.
State credits generally reach only research performed in the state, so the study records where each expense was incurred as it is built, not at filing time.
One base, two computations
- 1 Qualify the activities under the four-part test and total the year's QREs.
- 2 Compute the federal §41 credit and file it on Form 6765.
- 3 Apply the Connecticut entry above to the Connecticut share of that base, and file it on CT-1120 RDC / CT-1120 RC.
What the registry tells the preparer
These notes travel with the Connecticut entry inside the platform, reproduced verbatim for the person signing the return.
- §12-217n tiered non-incremental credit (1%/2%/4%/6% of CT R&D by spend tier) is stacked on the §12-217j 20% incremental credit.
- §12-217n ANTI-DOUBLE-DIP: a taxpayer claiming the §12-217j credit must reduce the R&D expenses taken into account under §12-217n by the excess R&E expenditures for which the §12-217j credit is given - the engine computes the tiered credit net of that increment.
- QSB (<=$70M gross income) credit exchange: 65% cash refund of unused credit (90% for qualified small biotech).
Registry sources
The citations the Connecticut registry entry carries, verbatim: what the study cites and a reviewer can check.
- Statute
- Conn. Gen. Stat. §12-217j (20% incremental); §12-217n (tiered non-incremental)
- Form
- CT-1120 RDC / CT-1120 RC
Registry entry version 2024.1, exported from services/study-api/app/engines/rules_engine.py (STATE_RULES_2024 + STATE_RULES_REGIME_OVERRIDES via RulesEngine.get_state_rules) on September 10, 2026. The entry above governs TY2026; a study for an earlier year uses that year's entry.
See what a Connecticut study could capture
Tell us what your team builds and we will come back with what a Ricerca study could capture: the federal §41 credit, the Connecticut credit above it, and the §174A deduction. Free, and no obligation.