A message sent to providers from the Department of Health and Human Services’ office of the inspector general on Monday said investigators would be “minimizing burdens” and relaxing reporting deadlines, but continuing to look for malfeasance or fraudulent billing.

Hospital groups welcomed the changes, many of which they had requested in letters to the agency. “I’ve never been in a situation where hospitals needed so much relief, both regulatory and financial, and I’m impressed here that C.M.S. has really taken on the issue and analyzed it well,” said Chip Kahn, the president of the Federation of American Hospitals, a trade group for for-profit hospitals. The American Medical Association, the largest doctors’ group, also welcomed the new rules.

Many of the announced changes would still be subject to state approval. But Ms. Verma said she hoped the new federal guidance would smooth the way for states to make such changes as they see fit.

New rules for doctors would make it easier for medical providers to be paid by Medicare. The government is allowing doctors in private practice to immediately begin treating Medicare patients in hospitals as their services are needed, even if they are not certified as Medicare providers, or are licensed out of state. It will also relax rules about the supervision of medical trainees. Medical residents can now be supervised by senior physicians over video or telephone, instead of only in person.

Supervision requirements will also be loosened for nurse anesthetists, nurse practitioners and other health professionals who typically work under the supervision of a physician. States will have the final say over how independently those professionals will be allowed to work.

The agency says the changes are allowed by the president’s declaration of a national emergency. They will last only for the duration of that emergency.

The agency said Medicare would broaden the range of services it would pay for, including care that is not in a traditional medical office or hospital. It would also cover more digital visits called telemedicine as well as more services that can be delivered in a patient’s home, such as testing for the coronavirus. Those rules apply directly only to the Medicare program. But the largest trade group for private insurers has said it will match Medicare’s waivers of normal payment rules for coronavirus, meaning the changes may have much broader reach.