Withholdings are your payment plan to Uncle Sam.
Remember, a tax refund is just the tax overpayment from your prior year withholdings, once all the income/deductions/adjustments ect.. are taken into account at the end of the year.
If you're getting a refund, it sounds like your withholdings from your W2 and 1099R are sufficient to cover your taxes once your income (e.g. from a W2, interest, dividends, etc..) is included.
It may be worth adjusting your federal withholdings (either with your employer or with the 1099R provider, or both) once or twice per year to make sure you're contributing the right amount through withholdings so you don't end up with either:
- penalties at the end of the year for contributing too little,
- an unnecessarily large refund.
The IRS has a pretty good withholdings calculator I do a in August and November each year:
https://www.irs.gov/individuals/tax-withholding-estimator
Why August and November? Updating withholdings in August still leaves 4 full months for any changes to take effect while a smaller November adjustment allows you to set things up for the end of the calendar year and the start of the next year.
