Keeping Our Commitment to Ending Veteran Homelessness Act of 2018 This bill extends through FY2019 authority for the following Department of Veterans Affairs (VA) programs: homeless veterans reintegration programs, the homeless women veterans and homeless veterans with children reintegration program, referral and counseling services for certain veterans at risk of homelessness, treatment and rehabilitation services for seriously mentally ill and homeless veterans, and the grant program for homeless veterans with special needs. The bill extends through FY2020 authority for the following VA programs: housing assistance for homeless veterans, and financial assistance for supportive services for very low-income veteran families in permanent housing. The bill extends through 2019 authority for the Advisory Committee on Homeless Veterans.