申请父母来美 您好，如果您没有报税或者报税的不够的，那么可以使用银行中的现金代替。移民局的规定是

Assets must equal the stated difference between the petitioner/sponsor’s household income and 125%(100% if military) of the poverty guideline.

*asset must equal the difference for applicants filing as orphans , a spouse, or child of an active duty military member
*asset must equal three times the difference for a spouse or child of a united states citizen
*asset must equal five times the difference for all others

Such evidence of assets includes:
*Bank statements covering the last 12 months, or a statement from an officer of the bank or other financial institution in which the sponsor has deposits, including deposit/withdrawal history for the last 12 months, and current balance;
*Evidence of ownership and value of stocks, bonds, and certificates of deposit;
*Evidence of ownership and value/equity of other personal property and dates acquired;
*Evidence of ownership, a recent licensed appraisal or country tax assessment and any mortgage/lien or lien release of any real estate.

假设您没有收入，那么申请父母两个人来美，那么您的银行中的现金数量要等于贫困线的125%减去您的收入*5*2=$20,025*5*2=$200,250

报税标准可以参考https://www.uscis.gov/sites/default/files/files/form/i-864p.pdf