Final answer:
Christine and Doug will be required to pay $4,350 in Medicare tax with their 2019 income tax return.
Step-by-step explanation:
To calculate the Medicare tax for high-income taxpayers, we need to know the gross annual income of Christine and Doug. Since Christine earns $250,000 and Doug earns $50,000, their combined gross annual income is $300,000. The Medicare tax rate is 1.45%, and it applies to all earned income.
So, the amount of Medicare tax Christine and Doug will be required to pay with their 2019 income tax return is:
Medicare tax = Gross annual income × Medicare tax rate
= $300,000 × 0.0145
= $4,350