Conn. Gen. Stat. § 12-263b

(b) Each hospital shall, on or before the last day of January, April, July and October of each year, render to the Commissioner of Revenue Services a return, on forms prescribed or furnished by the Commissioner of Revenue Services and signed by one of its principal officers, stating specifically the name and location of such hospital, and the amount of its net patient revenue as determined by the Commissioner of Social Services. Payment shall be made with such return. Each hospital shall file such return electronically with the department and make such payment by electronic funds transfer in the manner provided by chapter 228g, irrespective of whether the hospital would otherwise have been required to file such return electronically or to make such payment by electronic funds transfer under the provisions of chapter 228g.

(c) Notwithstanding any other provision of law, for each calendar quarter commencing on or after July 1, 2015, and prior to January 1, 2016, the amount of tax credit or credits otherwise allowable against the taxes imposed under sections 12-263a to 12-263e , inclusive, and 12-263i shall not exceed fifty and one one-hundredths per cent of the amount of tax due under sections 12-263a to 12-263e , inclusive, and 12-263i with respect to such calendar quarter prior to the application of such credit or credits. For each calendar quarter commencing on or after January 1, 2016, and prior to January 1, 2017, the amount of tax credit or credits otherwise allowable against the taxes imposed under sections 12-263a to 12-263e , inclusive, and 12-263i shall not exceed fifty-five per cent of the amount of tax due under sections 12-263a to 12-263e , inclusive, and 12-263i with respect to such calendar quarter prior to the application of such credit or credits. For each calendar quarter commencing on or after January 1, 2017, and prior to January 1, 2018, the amount of tax credit or credits otherwise allowable against the taxes imposed under sections 12-263a to 12-263e , inclusive, and 12-263i shall not exceed sixty per cent of the amount of tax due under sections 12-263a to 12-263e , inclusive, and 12-263i with respect to such calendar quarter prior to the application of such credit or credits. For each calendar quarter commencing on or after January 1, 2018, and prior to January 1, 2019, the amount of tax credit or credits otherwise allowable against the taxes imposed under sections 12-263a to 12-263e , inclusive, and 12-263i shall not exceed sixty-five per cent of the amount of tax due under sections 12-263a to 12-263e , inclusive, and 12-263i with respect to such calendar quarter prior to the application of such credit or credits. For each calendar quarter commencing on or after January 1, 2019, the amount of tax credit or credits otherwise allowable against the taxes imposed under sections 12-263a to 12-263e , inclusive, and 12-263i shall not exceed seventy per cent of the amount of tax due under sections 12-263a to 12-263e , inclusive, and 12-263i with respect to such calendar quarter prior to the application of such credit or credits.

See Ch. 211c re hospitals tax.