Thanks for the response.
The Transformation is not matching the ELIN number from CER, it is matching the 4-digit DN of the phone that made the 911 call.
The Transformation is set to match 6606, and prefix 860555, so the Caller ID is 8605556606.
This works for regular calls.
For 911, CER is setting the ELIN to 2079110000.
(this is in a lab environment, so not real numbers being used)
But when DN 6606 dials 911, the call is seen as 8605556606, even though the ELIN from CER is set to 2079110000
If I dial 911 from a different DN that does not match the Transformation, the ELIN is sent out correctly.