Deductions & credits

@cindy0213 There it is, Cindy, at the top of p 4 in publication 969, as @Opus 17 just pointed out.

 

Since you have apparently NOT filed yet, perhaps the simplest resolution is NOT to claim your son as a dependent in 2022. In that case, it appears to me his HSA is okay. (what do you think @Opus 17 ?)

Otherwise, his HSA is not okay, and to get things right, he would need to reverse the contribution for 2022 etc. This kind of thing happens with employers, as the person filling out the forms is often focused on other things. My son, for instance, has had trouble with excess contributions to 401k's both times he's switched employers (he's on his third job over the last 10 years.) Welcome to adulting, I guess....

 

My guess is that the IRS might not have a computer screening for this, so it might just drift on down the river if neglected, but then again, they might!