According to multiple press reports, the Congress has not included an extension of the timeline for the certification of the 737 MAX 7 and 10 in the annual "defense policy bill", actually the NDAA, National Defense Authorization Act. Since the NDAA is annually a must-pass legislative measure, often times "riders" are attached to it, to ease their passage.
Options for getting an extension done in this Congress are narrowing (insert details of legislative process here).