The Trump administration is formalizing new guidance to recommend that many, if not almost all, Americans wear face coverings when leaving home, in an effort to slow the spread of the new coronavirus.

The recommendations were still being finalized Thursday. They would apply at least to those who live in areas hard-hit by community transmission of the virus that causes COVID-19.

A person familiar with the White House coronavirus task force’s discussion said officials would suggest that non-medical masks, T-shirts or bandannas be used to cover the nose and mouth when outside the home — for instance, at the grocery store or pharmacy. Medical-grade masks, particularly short-in-supply N95 masks, would be reserved for those dealing directly with the sick.

The person spoke on condition of anonymity to discuss the proposed guidance before its public release.