Minimums used to be forbidden by many merchant agreements, but due to the federal Dodd-Frank Act from 2010, merchants can set credit card minimums up to no more than $10, as long as they set the same minimum for all types of credit cards they accept. This applies nationwide including NYC. Higher minimums are indeed still illegal, though that doesn’t mean you won’t still see them sometimes.

This provision of the Dodd-Frank Act does not cover debit cards, and I believe merchant agreements still prohibit minimums for debit cards. This prohibition is widely violated. I have no idea whether this prohibition is officially applicable to debit cards when they are processed as credit cards (which usually means no PIN for most US cards) - I’ve heard people say it’s not - but it definitely covers debit cards when they are processed as debit cards (which again for most US cards is always the case if a PIN is input).

As for NY’s current rules on price differences for credit cards vs cash and debit cards vs cash and the required disclosures, those are a bit complex, so I’ll just link an official explanation here:

https://dos.ny.gov/news/consumer-alert-nys-division-consumer...

But the TL;DR is, yes different pricing is legal if worded and disclosed correctly. To nobody’s surprise, illegal implementations remain common as well.