Form 8960 : Part 3, line 14

If filing status is:
Married filing jointly - $250,000
Married filing separately - $125,000
Qualifying widow(er) - $250,000
All other filing statuses - $200,000

IRS Form 8960, Net Investment Income Tax Individuals, Estates, and Trusts Instructions page 19 - https://www.irs.gov/pub/irs-pdf/i8960.pdf#page=19