You have to file Form 8959 if the Medicare wages or RRTA reported exceed $200,000 for single filers or $250,000 for joint filers.
If you have self-employment income, you file form 8959 if the sum of your self-employment earnings and wages or the RRTA compensation you receive is more than the threshold amount for your filing status.
See the below TurboTax link for additional information.
https://turbotax.intuit.com/tax-tips/health-care/what-is-form-8959-additional-medicare-tax/L62vNXoy5
