S&P Global Ratings placed all its ratings on CareCore National LLC on CreditWatch with positive implications.
CareCore National changed its name to eviCore healthcare LLC in December 2014.
The ratings move comes after pharmacy benefit manager Express Scripts Holding Co. agreed to acquire eviCore for $3.6 billion.
The ratings placed under CreditWatch include the B long-term corporate credit rating and senior secured debt ratings.
The agency said the company's growth prospects were largely positive, as its services had been gaining traction with healthcare payers.
S&P Global expects to resolve the CreditWatch once the deal with Express Scripts closes in the fourth quarter of 2017.
The agency said it may upgrade CareCore by multiple notches depending on the integration with Express Scripts.
S&P Global Ratings and S&P Global Market Intelligence are owned by S&P Global Inc.