Need some assistance in this complex area, with which I am not that familiar.

Facts:
Owner owns 100% of medical management company, which provides billing, management, etc services to 4 medical practices.
Owner owns 20% of medical practice #1, <5% in other 3 medical practices.
Medical Management Co's revenue evenly split - approximately 25% from each medical practice.

Is this an affiliated svc group, and which companies are included?

Thanks for any assistance.

I am far from an expert in the area (as if anyone is, except maybe for Derrin Watson)

however, according to the IRS notes (see page 7-72 of the attachment - IRS notes on Controlled and Affilaited Service Groups)
you have
1. an organization that performs management functions
2. [maybe] the management organization's principal business is performing management functions on a regular and continuing basis

common ownership is not important.

Click to view attachment

so, based on that, I believe you need to test to see if the principal business is satisfied for each group.
see page 7-75 and the example

Might also have a B-org. between medical practice #1 & the management company.

My understanding is that for a management ASG, the management service provider must derive more than 50% of its revenues from just one recipient organization, and if so the ASG is composed of just that recipient and provider organizations. Since the I would think there would be no management ASG unless of those 4 recipients, those that provide on a combined basis more than 50% of the management service provider's revenues are themselves a controlled group or ASG.