The Connecticut entry, field by field
This is the registry entry our engine applies for tax year 2026, rendered field by field. Where a field is blank in the registry, the row says so rather than filling the gap.
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 expense base as the federal §41 credit, using the registry entry for the tax year claimed and applying the state's own qualification rules to it. Where the registry is silent on a point, the study says so and the position is resolved with the return preparer instead of being assumed.
Claiming it alongside the federal credit
The federal §41 credit comes first. It is computed from the qualified research expenses the study substantiates - wages for qualified services, supplies consumed in research, computer and cloud rental, and the allowable share of contract research - and it lands on Form 6765 with the return.
The Connecticut credit is then computed from that same substantiated base, with the state's own rules applied on top: its rate, its base amount, its caps, and its own view of what counts. Where the work was physically performed matters: state credits generally reach the research done in the state, so the same employee can sit inside one state's base and outside another's.
That is why the allocation work is done once, at the expense level, with the state attribution recorded as it is built rather than reverse-engineered 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 and are reproduced here verbatim, including the registry's own emphasis. They are written for the person signing the return, which is exactly why they belong on a page about the credit.
- §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).
Sources
The citations below are carried verbatim on the Connecticut registry entry. They are what the study cites, and what 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 registry is versioned per state and per tax year: the entry above governs TY2026, and a study for an earlier year is computed under that year's entry instead.