Texas has a franchise tax This is essentially a state income tax on entities. Sole proprietorship are excluded, so if you have formed a corporation to allow you to deduct business expenses from 1099 income without getting hit by the AMT (alternative Minimum tax).
In Texas Physicians and dentists were able to form P.A. (professional associations) which were immune from the franchise TAX. Other professionals, accountants, lawyers, engineers and CRNAs had to form P.C. (professional corporation) or a LLC and had to pay the 5% franchise Tax.
This has recently changed so now Physicians and all other entities are treated equally and have to pay the 5% franchise tax on any income over the fist $300,000. Texas has no state Income Tax so the legislature is always looking for more money to spend buying votes and to benefit wealth lobbyists on worthless pork barrel projects. I am not sure of all the details but now physician are treated equally with other business entities and are not taxed on the first $300,000 of income. The revenue lost by not taxing the first $300,000 has been offset by a new gross receipts tax on most business entities, which I think physicians are exempt.
The net effect is that now Texas physicians entities have a 5% tax on all income over $300,000 and now have to file a State corporate income tax statement.
If you are looking for a low tax state to claim residence for 1099 income while traveling and working various locums assignments. I think Nevada clearly wins over Texas, Florida, Tennessee and New Hampshire. (TN, FL, NH have taxes on investment income and a wealth tax on net worth) I do not have any knowledge of Wyoming, South Dakota, Alaska and Washington.