The stable outlook on Exelon Generation Co. LLC (ExGen) mirrors those on parent Exelon Corp. because of ExGen's core status to Exelon. That status implies the ratings on ExGen are supported by and linked to Exelon. The stable outlook also reflects our expectations that Exelon's lower-risk utility operations and less volatile zero-emissions credits (ZECs) will consistently reflect about 75% of consolidated EBITDA. While the issuer rating on ExGen is predicated on Exelon maintaining adjusted funds from operations (FFO) to debt at more than 19%, in order for ExGen to maintain a 'bbb' stand-alone credit profile (SACP), we expect it to maintain adjusted FFO to debt of at least 35%. ExGen's FFO to debt was about 34% in 2017, but ZEC