Are you the only member of your LLC, or are there other members? A single-member LLC is disregarded (ignored) for income tax purposes. But if there is more than one member the LLC has to file a partnership tax return. If the company that you work for has a contract with the LLC or pays the LLC rather than paying you personally, you might have to file partnership tax returns in the states where you worked. If you have a multi-member LLC you should consult a local tax professional who specializes in multi-state taxation.
An LLC, single-member or multi-member, can file an election with the IRS to be treated as an S corp or a C corp for tax purposes. Has your LLC made such an election?
Does the company that you work for pay you as an employee (you get a W-2) or as an independent contractor (you get a 1099-NEC or 1099-MISC or no tax form)? Some of the states that you work in might have different rules for an independent contractor or an LLC than for a W-2 employee. If you are an independent contractor then, again, you should consult a local tax professional who specializes in multi-state taxation.
