If you are receiving a pension from another state and don't receive a subsistence allowance, you should report your pension income on your federal return and your current state's tax return. Generally, you pay state income tax to the state where you are a resident, not the state where you earned or qualified for the pension
However, state tax laws can vary, so it's important to check your current state's rules regarding out-of-state pensions
For more detailed information, you can refer to the IRS guidelines on taxation of retirement income and the Retired Public Employees Association for state-specific tax information.