https://www.firsttouchsoccer.org/schedule.html

Indoor or outdoor. I think you could pay by the session.

Here are the options I know of in the area:

Arlington. Winter and Summer. Separate sessions for K-8 & HS Age: http://www.arlingtonsoccer.com/programs/other-programs/drop-in-soccer

PG Young Boys (PG County). They call them "open runs" - winner stays on, very competitive, attracts some high level players. Site not updated for winter but it's worth checking in case something pops up: https://www.pgyoungboys.com/futsal-open-run.

PWSI. Possibly summer only. https://www.pwsi.org/openplay

FPYC: Used to be Fridays and Sundays but for now it looks like just Sundays at Stafford: https://fpycsports.demosphere-secure.com/sports/soccer/field-calendars/stafford-park-1.

Is there anywhere in NWDC / MoCo for pick-up or drop-in soccer for high-schoolers?

My son played soccer throughout childhood, and while he didn't end up playing travel, he loves to play and would love to find a low-key, low-commitment opportunity to get a ball at his feet. He doesn't want to formally join a team, as he has other commitments and it wouldn't make sense -- but he'd love to play from time to time, if not somewhat regularly.

Indoor? Outdoor? He's pretty big and could manage with adults, but from what I've seen most of the adult drop-in / pick-up stuff is age 16+, and he's not quite there yet.

Thanks in advance.