This is a relatively old post but it was recently brought to my attention, so I'm bringing it back to the top with this reply...
The original question is more of an agency-level question, particularly where First Steps is concerned, and as a contracted provider, I'm not as familiar with the agency-level procedures to enroll as a First Steps Multidisciplinary Agency, but here's a link from the Indiana FSSA website:
FSSA: First Steps: Become a First Steps Multidisciplinary Agency
I'm afraid that as far as Medicaid is concerned, I know even less, but here's a link from Indiana Medicaid for Providers:
Indiana Medicaid: Providers: Become a Provider
The original poster has probably graduated and moved on - hope they are finding much success and hope this might help any other providers trying to boost their agency's profile and income/resources