Gift to you is NOT income and not taxable. Suggest you deposit less than $5000 one time. Although banks are required to report to IRS any cash received for $10,000 or more, the common pratice is that they will report amount lower than that (probably $8000) to cover themselves. This is to prevent money laundry or illegal income. If your mother didn't report the cash to custom, you should be concerned to prove this is actually gift rather than income, if you ever being questioned.