The US federal government has entered a shutdown due to a budget standoff between Republican and Democratic lawmakers, leading to significant disruptions across various sectors. Approximately 750,000 federal employees are on unpaid leave, with essential services like air traffic control and TSA operations continuing without pay. Travelers may experience delays, and passport processing times could increase. National parks are likely to close or operate with minimal staff, raising concerns about vandalism and safety. Social health programs, including Medicare and Medicaid, will continue but may face staffing shortages. Food assistance programs are at risk of running out of funds, while the US Postal Service remains unaffected. The shutdown's duration is uncertain, prompting worries about its long-term effects on federal services and employees.