Miss. Code § 83-5-913
If a health insurance issuer requires prior authorization of a health care service, the health insurance issuer must make an approval or adverse determination and notify the enrollee, the enrollee's health care professional, and the enrollee's health care provider of the approval or adverse determination as expeditiously as the enrollee's condition requires but no later than seven (7) calendar days after obtaining all necessary information to make the approval or adverse determination, unless a longer minimum time frame is required under federal law for the health insurance issuer and the health care service at issue. As used in this section, "necessary information" includes the results of any face-to-face clinical evaluation, second opinion or other clinical information that is directly applicable to the requested service that may be required. Notwithstanding the foregoing provisions of this section, health insurance issuers must comply with the requirements of Section 83-9-6.3 to respond by two (2) business days for prior authorization requests for pharmaceutical services and products.
Miss. Code § 83-5-913