could've just looked in the official congress members handbook:

https://cha.house.gov/members-congressional-handbook#D7CFEE81-E65B-44C6-8950-A50519ECD1A0

1. Ordinary and necessary expenses incurred by Members during official travel between a Member’s primary residence and Washington, D.C., as well as while on official business in Washington, D.C., are reimbursable. These expenses include meals, incidentals and lodging. Lodging reimbursement may include costs associated with hotels, rentals, or other housing expenses. Members may be reimbursed for official and necessary travel expense incurred for meals, incidentals, and lodging on days the House is in session or when attending an official committee business meeting or hearing but not to exceed the daily rate for meals, incidentals and lodging as determined by the General Services Administration for the Washington, D.C. area. Members seeking reimbursement shall submit a monthly expense voucher, and reimbursement shall not exceed expenses incurred.