Retirement tax questions

So what reporting is done by a custodian to the IRS when someone inherits an IRA? For example, let’s say Schwab puts $100,000 worth of different stocks into a new Inherited IRA account for the main Trust after the paperwork (application) is filled out upon a decedent’s death. Doesn’t the IRS have to know at a minimum about the new account in the main Trust? Not to mention the movement of money from this new account into 2 new Sub Trust Inherited IRA accounts.