Miss. Code § 41-87-15
Any federal funds made available to the state through Part C and any additional state funds appropriated for early intervention services after July 1, 1990, shall be used to supplement and increase the level of state, local and other federal funds that were expended for eligible children and their families before July 1, 1990. Funds provided under Part C may not be used to satisfy a financial commitment for services that would have been paid for from another public or private source if Part C money did not exist, except that whenever necessary to prevent a delay in the receipt of appropriate early intervention services by the infant or toddler or family in a timely fashion, Part C funds may be used to pay the provider of the services pending reimbursement to the lead agency from the agency that has ultimate responsibility for the payment.
Miss. Code § 41-87-15