Final answer:
Matilda does not need to include anything in her 2019 gross income since she withdrew the same amount that was contributed to her health savings account and earned as interest.
Step-by-step explanation:
To determine the amount that Matilda must include in her 2019 gross income, we need to calculate the total contributions to her health savings account (HSA) and any interest earned, and subtract the amount she withdrew to pay for medical expenses.
In 2018, Matilda's employer contributed $1,500 to her HSA. In 2019, the employer again contributed $1,500, and the account earned $100 in interest. Therefore, the total contributions and interest are $1,500 + $1,500 + $100 = $3,100.
However, Matilda withdrew $3,100 from the account to pay for her medical expenses. Since this equals the total contributions and interest, Matilda does not need to include anything in her 2019 gross income.