Legislators and concerned citizens, be aware: taxophilic previous generations of Rhode Island lawmakers have written the minimum tax imposed on businesses into two separate places in the law. State law contains separate provisions for a “franchise tax” and a “minimum corporate income tax” and for many if not most Rhode Island corporations, both sections would need be modified in order for them to see a change in their minimum tax liability.
Section 44-11-2(e) of RI law specifies the minimum corporate income tax…

The tax imposed upon any corporation under this section shall not be less than five hundred dollars ($500).

However, most of section 44-11 does not apply to certain corporations in Rhode Island, as spelled out in section 44-11-2(d)…

A small business corporation having an election in effect under subchapter S, 26 U.S.C. section 1361 et seq., shall not be subject to the Rhode Island income tax on corporations, except that the corporation shall be subject to the provisions of subsection (a), to the extent of the income that is subjected to federal tax under subchapter S.

Which means, I believe, that S-corporations are exempt from corporate income taxes, including the minimum, while C-corporations and limited-liability corporations (LLCs) have to pay them. (At least, that is what state tax-forms seem to indicate, where S-corps are referred to in a different section from the C-corps and the LLCs).
The franchise tax is defined in the next chapter of the law, in section 44-12-1(a), with no blanket exception for S-corps…

Every corporation, joint-stock company, or association incorporated in this state or qualified to do business in this state, whether or not doing business for profit, all referred to in this section under the term “corporation”, except those enumerated in section 44-12-11, shall pay an annual franchise tax to the state upon its authorized capital stock of two dollars fifty cents ($2.50) for each ten thousand dollars ($10,000) of such stock or fractional part, or the sum of five hundred dollars ($500), whichever is greater, thereof.

Corporations however are prevented by section 44-12-1(b) from paying a double minimum tax…

In the case of corporations liable to a tax under chapter 11 of this title, only the amount by which the franchise tax exceeds the tax payable under that chapter shall be assessed.

In other words, in cases of C-corps and LLCs that have an income tax liability greater than or equal to their calculated franchise tax liability, their income tax counts as their franchise tax too.
Both sections of corporate tax law must be considered when determining how a proposed change to minimum taxes will impact liabilities, even when a proposed change is only being applied to one tax or the other. And, as currently written, several of the minimum business tax bills that have been introduced to the legislature, if adopted in isolation, appear not to change the tax liabilities of Rhode Island businesses at all.
Representatives Stephen Ucci (D-Johnston/Cranston), Peter Petrarca (D-Johnston/Lincoln/Smithfield), Joy Hearn (D-Barrington/East Providence), Robert Phillips (D-Woonsocket), and Peter Martin (D-Newport) have introduced a bill (H5153) that reduces the minimum corporate income tax specified in 44-11-2(e) to $50. If no other change to the law is made in conjunction with H5153, the tax-liability of corporations covered by the franchise tax (i.e., most RI corporations) will remain unchanged. The franchise tax will still exist, meaning that a corporation would continue to owe the same $500 under the new law that it owed under the old law, now in the form of a $50 corporate minimum income tax, plus the $450 difference between the franchise tax and the income tax. (And an S-Corp that didn’t owe the income tax would still owe the $500, all as franchise tax).
Representatives Gregory Schadone (D-North Providence), Jan Malik (D-Warren/Barrington), and Arthur Corvese (D-North Providence) have introduced a bill (H5167) with an identical structure to H5153, differing only in that it changes the minimum income tax to $250. Again, this bill by itself would not reduce the tax-liabilities of corporations that owe the minimum franchise tax.
A bill (H5060) introduced by Representatives Donna Walsh (D-Charlestown/New Shoreham/South Kingstown/Westerly), Patricia Serpa (D-West Warwick/Warwick/Coventry), Frank Ferri (D-Warwick), Larry Valencia (D-Exeter/Charlestown/Richmond), and Deborah Ruggiero (D-Jamestown/Middletown) modifies the minimum corporate income tax by introducing a graduated scale. At the low end, corporations to which it applies (i.e. C-Corps and LLCs) that in a given year record less than $250,000 in gross receipts would have no income tax liability — but again, if no additional change to the law is made, the amount of taxes owed would not change because the C-corps and the LLCs would still owe the state the difference between $500 franchise tax and the $0 corporate minimum income tax.
Representatives Doreen Costa (R-North Kingstown/Exeter), Larry Ehrhardt (R-North Kingstown), Mike Chippendale (R-Foster/Coventry/Glocester), and Dan Gordon (R-Portsmouth/Tiverton/Little Compton) have been working the problem from the other end, introducing a bill (H5100) that would repeal the franchise tax in its entirety . This is a little better than the previous measures, as the S-Corps exempted from 44-11 would no longer have to pay a minimum tax or a franchise tax. However C-corps and LLCs would still have to pay the $500 minimum income tax specified in 44-11-1 even in the absence of the franchise tax. (Also, there could also be impacts from this law as you move up the scale away from the minimum, depending on whether a particular company currently has a greater liability computed from the franchise tax or the income tax).
Finally, State Senators Nick Kettle (R-Coventry/Foster/Scituate), Christopher Ottiano (R-Bristol/Portsmouth), David Bates (R-Barrington/Bristol), Dawson Hodgson (R-East Greenwich/Warwick/North Kingstown), and Glen Shibley (R-Coventry/Warwick/West Warwick/East Greenwich) have introduced a Senate bill which repeals both the minimum franchise tax and the minimum corporate income tax (S0103). This piece of legislation, where both the franchise tax and the corporate minimum income tax are changed at the same time, is the model that should be used in order to really effect a change in the current system.