Kristen has an individual medical expense policy with a $2,000 calendar-year deductible, a $5,000 annual out-of-pocket limit, and a 20 percent coinsurance requirement. Kristen's out of pocket limit applies to coinsurance only. Kristen was hospitalized for a surgical procedure in March, her first health care treatment received during the year. The total bill was $20,000. Considering the deductible and coinsurance, how much of this amount must Kristen pay.