Your question is a bit vague as you don't use a verb.
Two things come to mind:
1. Banks are required to inform the IRS of cash deposits in the amount of $10,000 or greater in order to track the influx of illicit transactions. Drugs, weaponry, unsavory criminal acts...all tend to dispense with the customary paper trail and operate on a cash basis. I used to perform in orchestras and always shied away from organizations paying me in cash for that told me gangsters were involved and I didn't want to be part of their arrangement. I'll pay my rightful share of taxes, thank you.
2. You will need to represent yourself to the IRS or FBI if questioned over an inordinate sum of cash deposited into your bank account. Some might say it's unfair or smacks of over-controlling government folks bent upon making a name for themselves but the fact is that our country must defend against criminals who would sell out anyone for the sake of illicit gains. So in such a case, you will want and need a letter explaining the circumstances by which you have come into $10K or greater as made visible by a cash deposit.
I've been saving coins from daily transactions for years. I suspect it amounts to more than $5,000 and in time will likely exceed $10,000. Rather than walk knowingly into a potentially difficult audit despite my innocence relative to wrongdoing, it would be better to spend the cash rather than make a questionable deposit.
Professional stock analyst & trader; energy consultant.