A county is financially responsible only for the hospitalization expense which is beyond the person's ability to pay. A person's ability to pay is determined according to the following: (1) Determine the household's contributions for taxes, social security, medicare, and payments to other standard retirement programs. A household's contribution for taxes is limited to the amount of taxes payable for the actual number of dependents in the household; (2) Determine the household's expenses, including actual rent paid or scheduled principal and interest payments for a personal residence plus property taxes and homeowner's insurance costs; all utilities; child care expenses related to work schedules; grocery expenses up to the maximum allowed under the Food Stamp Program's Thrifty Food Plan as specified in rules promulgated by the Department of Social Services pursuant to chapter 1-26 , plus household supplies and toiletries; basic auto expenses, gasoline, and upkeep; employee - paid health, life, and auto insurance payments; installment payments for medical bills; recurring expenses for medicine and medical care; court - ordered child support and alimony paid; automobile installment payments for one vehicle; clothing, reasonable in relation to the household's income; and installment payments, limited to necessary household items required by the household to maintain the needs of everyday living and reasonable in relation to the household's income; (3) Determine the amount of a household's discretionary income by subtracting the sum of the household's contributions and expenses from the household's income determined according to §