There are three "intercept zones" from which Dr Bill Exchange can receive and subsequently return bills.  Each of these corresponds roughly to a different strategic use of the Exchange.  You can use more than one intercept zone at a time (it is being done now).  And it is quite easy to migrate from one zone to another, typically moving from "later" zones to an "earlier" one.

The Early Cycle zone supports the most aggressive use of the Exchange.  It picks up bills from or shortly after data entry, and uses the Exchange's powerful bill management tools to route and deliver bills to all re-pricing, analytics, and other destinations.  This means you control the bill through its entire life cycle, and can use different vendors, including bill review vendors, based on jurisdictions, or other criteria.  You can build a process as complex as you like, even for different clients.  And most importantly, you can change it quickly and easily with no impact to internal systems, to respond to legislative or market conditions.

The Mid Cycle zone is convenient for payers who have a committed early cycle process, including data entry, medical edit, fee schedule/UCR, and other bill review activities.  Often, mid-cycle implementation take advantage of pend-and-transmit facilities, which are available in many commercial and proprietary bill review systems.  This approach lets you use both existing vendors and new ones connected through Dr Bill, and migrate from one to the other as desired over time.

The Late Cycle zone is often an intercept as bills complete their existing process and are about to be fed into their system of record (claims, payment, etc.).  There are two subcategories of usage.  If the payer has good control over re-pricing vendor routing in their current system, and can 'turn off' functions or vendors, this approach is just as powerful as the mid-cycle approach, and often easier to implement.  If there is limited or no control over the prior process, then the target is 'low hanging fruit" -- bills of certain types, or for certain jurisdictions, which typically find little savings in the current process.

It is sometimes useful to intercept bills at multiple intercept zones simultaneously for various purposes, a technique already being used in production.  But in general, these multiple modes of implementation allow you to begin using the Exchange conservatively, and over time increase its use and your control of the process.  It is important that this transition be supported, as it is prudent not to disturb vendors and parts of the process that are working well for you at the time.