There are some codes that can be used for asynchronous portal messages, but to be honest the AMA is still pretty broken as far as how much time we need to spend for things... the codes are 99421 (5-10 minutes over 7 days), 99422 (11-20 minutes), 99423 (21+). It is not clear to me how well these codes are actually paid for by private insurance. In a wRVU system a PCP may get paid like $5-13 for the first code, $15-30 for the 2nd, $24-44 for the 3rd. This is a lot less than a visit... and you must spend the minimum 5 minutes on the portal message or you are billing it fraudulently. I can cover an in person level 4 visit (99214) in 5 minutes in some cases, which pays something like $100.