Nominated in 2019, Captain Harrington serves as Deputy Associate Administrator for Federal Sealift, within the U.S. Department of Transportation’s Maritime Administration (MARAD), his portfolio includes responsibility for federal sealift programs that provide for the Nation’s requirements during peacetime, civil contingencies, and wartime.

Captain Harrington completed Harvard Kennedy School's Senior Managers in Government program.

He is also, a graduate of the Maine Maritime Academy and served in the U.S. Navy as an Unrestricted Line officer, designated as a Surface Warfare Officer, and qualified as a Strategic Sealift Officer and a Joint Qualified Officer-Level III. Beginning in 1991, he served in the U.S. Merchant Marine, in 1997 he became a licensed Master Mariner. He completed the National Sealift Training Program, and for his U.S. Merchant Marine service during Operation Iraqi Freedom, he was awarded the Merchant Marine Expeditionary Medal. He remains licensed by the U.S. Coast Guard as a Master Mariner, Unlimited.

In September 2024, he began serving as the interim Associate Administrator for Strategic Sealift, MARAD’s senior executive for strategic sealift capabilities. He oversees programs including the Maritime Security Program, Tanker Security Program, Cable Security Fleet, and Federal assets of the National Defense Reserve Fleet (NDRF). He also retains responsibility for sustaining maritime capabilities including cargo preference activities, merchant mariner training, commercial strategic ports readiness, and participation with other Federal agencies, NATO, and commercial maritime partner organizations operating within the nation’s Marine Transportation System (MTS).