The House will begin consideration of the $491 billion Defense appropriations bill. A multitude of amendments are expected, so a vote on final passage will not come until Thursday.
The Senate starts at 9:30 a.m. and will spend the day debating a "minibus" spending bill.
Members will also vote on a motion to go to conference with the Senate on the Department of Veterans Affairs reform bills each chamber has passed.
On Tuesday, Senate Veterans Affairs Committee Chairman Bernie Sanders (I-Vt.) said he hopes conferees will be named, who will quickly iron out differences between the two measures.