Here is the current CDC guidance on a close contact with a COVID-infected person:

CDC Guidelines

 

You should still get tested if you’ve had close contact with someone who has COVID-19 or if you have symptoms of COVID-19.

• If you’ve had close contact with someone who has COVID-19, you should be tested immediately but no earlier than 2 days after exposure, and if negative be tested a second time at 5-7 days,  even if you don’t have symptoms. You should also wear a mask indoors in public for 14 days following exposure or until your test result is negative.
• If you have symptoms of COVID-19, you should get tested and stay home and away from others.
• If your test result is positive, isolate at home for 10 days.

So, isolation or quarantining isn’t necessary, unless you test positive or have symptoms.