Exhibit 21.1

Subsidiaries of Registrant as of March 31, 2022

Name:Digirad Health, Inc.

State of Incorporation:Delaware

Name:Digirad Diagnostic Imaging, Inc.

State of Incorporation: Delaware

Name:Digirad Imaging Solutions, Inc.

State of Incorporation:Delaware

Name:Project Rendezvous Holding Corporation

State of Incorporation:Delaware

Name:Project Rendezvous Acquisition Corporation

State of Incorporation:Delaware

Name:Star Real Estate Holdings USA, Inc.

State of Incorporation:Delaware

Name:947 Waterford Road, LLC

State of Incorporation:Delaware

Name:56 Mechanic Falls Road, LLC

State of Incorporation:Delaware

Name:300 Park Street, LLC

State of Incorporation:Delaware

Name:ATRM Holdings, Inc.

State of Incorporation:Minnesota

Name:KBS Builders, Inc.

State of Incorporation:Delaware

Name:EdgeBuilder, Inc.

State of Incorporation:Delaware

Name:Glenbrook Building Supply, Inc.

State of Incorporation:Delaware

Name:Star Equity Fund GP, LLC

State of Incorporation:Delaware

Name:Star Equity Fund, LP

State of Incorporation:Delaware

Name:Star Value, LLC

State of Incorporation:Delaware

Name:Star Investment Management, LLC

State of Incorporation:Connecticut