Answer:
Additional Medicare is charged on the wages that are higher than $200,000.
1. Medicare owed assuming Ms. Deming is single:
= (225,000 - 200,000) * 0.9%
= 25,000 * 0.9%
= $225
2. Medicare owed assuming Ms. Deming files a joint return with her husband.
When filed together, their wages would be considered jointly.
= ( (100,000 + 225,000) - 200,000) * 0.9%
= 125,000 * 0.9%
= $1,125
