Most large health systems no longer contract directly with the agencies that supply their contingent clinical labor. They appoint a managed service provider to run the program, and the agency's contract is with that intermediary. Aya, AMN, Cross Country, RightSourcing, HealthTrust and others operate this way, and it is now the normal shape of a mid-market nurse staffing account.
The consequence is not administrative. It changes whose credit supports your ledger. When the MSP is the party contractually obliged to pay you, your receivable is on the MSP. The hospital's name is on the badge, the assignment and the timesheet, and none of that makes the hospital your debtor. Any lender advancing against those invoices is underwriting the intermediary.
Agencies routinely present these accounts as investment-grade hospital exposure and are surprised when underwriting treats them differently. Sometimes the MSP is genuinely the stronger credit. Sometimes it is a thinly capitalized program manager passing through payments it has not yet received. The distinction is knowable before you sign, and it determines both your advance rate and your concentration headroom.
There is a second-order effect worth understanding. On a direct hospital account you have one payment cycle. On an MSP-intermediated account you have two, because the MSP generally pays you after it has been paid, whatever the stated terms say. Net-45 with the MSP behind net-45 with the health system is not net-45. It is the sum, plus the approval window between them.