Nomad.how does not infer a legal answer from destination and length. It turns your facts into a source-aware research record.
Start with the exact passport, residence, dates, payer, employer or client, activity, and place where work happens. Save the official source and the date you checked it.
Your research question is: what permission, if any, applies to a United States passport holder spending 60 days in Portugal for remote work for a foreign employer?
Entry permission does not necessarily authorize work.
Remote-work rules vary by jurisdiction and activity.
Rules, official pages, and interpretations can change.
Individual circumstances and professional advice may matter.