Substitute Bill No. 157 is a legislative proposal that, if enacted, would introduce a tax credit for research and development expenses for pass-through entities, effective January 1, 2025, and applicable to taxable years commencing on or after that date. The bill specifies that a credit of six percent of the research and development expenses paid or incurred by a taxpayer during the taxable year can be claimed against the tax imposed under chapter 229 of the general statutes, excluding the liability imposed by section 12-707. The definition of "research and development expenses" is to align with the meaning provided in section 12-217n of the general statutes. The credit can be claimed by shareholders or partners if the taxpayer is an S corporation or an entity treated as a partnership for federal income tax purposes, or by the owner of a single-member limited liability company that is disregarded as a separate entity.

Furthermore, the bill limits the total amount of tax credits that can be allowed by the Commissioner of Revenue Services to five million dollars in any fiscal year. It also authorizes the Commissioner of Revenue Services to adopt regulations to implement the purposes of this section. The bill includes insertions that indicate the new bill number (Substitute Bill No. 157) and the effective date of the provisions (January 1, 2025). There are no deletions indicated in the provided text.