I was wondering what the maximum amount is before I actually have to file a tax return.

1. Filing Status Single
*If under 65, must file tax return if gross income is at least $9,350.
*If 65 or older, must file tax return if gross income is at least $10,750.

2. Filing Status Married Filing Jointly
If under 65 (both spouses), must file tax return if gross income is at least $18,700.
If 65 or older (one spouse), must file tax return if gross income is at least $19,800.
If 65 or older (both spouses), must file tax return if gross income is at least $20,900.
(Read Filing Status: Married Filing Jointly)

3. Filing Status Married Filing Separately
Any age, must file tax return if gross income is at least $3,650.