More info...

At the current 400% threshold, a family of 4 is eligible for a refundable premium tax credit if their modified AGI (same as AGI for most people) does not exceed 400% of the poverty line. For a family of 4, the poverty line is $24,600 - so that family of 4 is eligible for a refundable credit if their income does not exceed $98,400.

The Senate bill changes the max threshold to 350%. A family of 4 would be eligible for a refundable credit if their MAGI does not exceed $86,100.

The Senate bill does not change the percentages and thresholds used to calculate the refundable credit. It merely cuts off people who make between $86,100 and $98,400 (family size of 4).

https://www.healthcare.gov/glossary/federal-poverty-level-FPL/