This document sets forth interim final rules implementing certain provisions of the No Surprises Act, which was enacted as part of the Consolidated Appropriations Act, 2021. These interim final rules amend and add provisions to existing rules under the Internal Revenue Code, the Employee Retirement Income Security Act, the Public Health Service Act, and the Federal Employees Health Benefits Act. These interim final rules implement provisions of the No Surprises Act that protect participants, beneficiaries, and enrollees in group health plans and group and individual health insurance coverage from surprise medical bills when they receive emergency services, non-emergency services from nonparticipating providers at participating facilities, and air ambulance services from nonparticipating providers of air ambulance services, under certain circumstances. In this rulemaking, the Department of Health and Human Services (HHS), the Department of Labor (DOL), and the Department of the Treasury (collectively, the Departments) are issuing interim final rules with largely parallel provisions that apply to group health plans and health insurance issuers offering group or individual health insurance coverage. HHS is also issuing in this rulemaking additional interim final rules that apply to emergency departments of hospitals and independent freestanding emergency departments, health care providers and facilities, and providers of air ambulance services related to the protections against surprise billing. The Office of Personnel Management (OPM) is issuing in this rulemaking interim final rules that specify how certain provisions of the No Surprises Act apply to health benefits plans offered by carriers under the Federal Employees Health Benefits Act (FEHBA).