Negative Income Tax (NIT) is a form of basic income that phases out as recipient earned income rises. NIT is composed of an "income floor" and a "phaseout rate". The income floor is the amount of cash a recipient with $0 of earned income receives. The phaseout rate is how much the cash benefit is decreased per additional dollar of earned income.
For example, consider an NIT with an income floor of $13,000 and a phaseout rate of 50%. A citizen with no income would receive $13,000 per year, often broken up into monthly payments. If the citizen gets a part-time job and begins earning $20,000 per year, they would still receive $3,000 per year in NIT benefits.