If the only tax forms you get are a RRB-1099 and RRB-1099-R are you required to file it with the state? No state taxes were taken out, and turbotax says no taxes are due when i run it for the state.

No, Railroad Retirement Board income is not taxable by the state so if you have no other income, you do not need to file.

Along the same lines, I'm filing my retired dad's taxes and the only annuity he receives is through the RRB (RRB-1099 and RRB-1099-R). Given RRB annuities are not taxable by states (https://www.rrb.gov/Benefits/IncomeTax/TXB-25), he shouldn't be paying MD tax on his RRB benefits. However, the MD state TurboTax module is insisting that part of his annuity is taxable. A CPA looked over his taxes (and also filed them last year) and they agreed and informed me that he should be refunded any taxes that were given to MD throughout 2019.