441—185.121 (234) Billing procedures. At the end of each month, the provider agency shall prepare Form 470-0020, Purchase of Service Provider Invoice, for contractual services provided by the agency during the month.
Separate invoices shall be prepared for each county from which clients were referred and each program. Complete invoices shall be sent to the department county office responsible for the client for approval and forwarding for payment.
Providers shall never bill for more than one month of service. A separate invoice is required for each separate month of service, even if the service span overlaps one month.
	 185.121(1) Time limit for submitting invoices. The time limit for submission of original invoices shall be 90 days from the date of service, except at the end of the state fiscal year when claims for services through June 30 are to be submitted by August 10.
	 185.121(2) Resubmittals of rejected claims. Valid claims which were originally submitted within the time limit specified in 185.121(1) but were rejected because of an error shall be resubmitted as soon as corrections can be made.
	 185.121(3) Payment. Within 60 days of the date of receipt of a valid invoice, the department shall make payment in full of all invoices concerning rehabilitative treatment and supportive services rendered to clients, provided the invoices shall be subject to audit and adjustment by the department.