According to the 2006 Rhode Island Standard of Need: "A two-parent family (in which both parents are working full time) can meet basic needs when the parents' joint earnings are $37,500 (185%, or almost twice, the Federal Poverty Level of $20,000) and they take advantage of childcare and healthcare subsidies. When the parents become ineligible for the healthcare subsidy (at income above 185% of the FPL), income is not sufficient to meet expenses. To meet basic needs without subsidies, a two-parent family needs annual gross earnings of approximately $60,000/year or $28.85/hour."
In other words, this family would lose a large share of benefit support relative to new earnings — and may be even worse off financially that before their earnings increased. This is what is known as a "benefits cliff."