It seems that you could be interested by the MasterCard SDK, specifically the ATM Locations web service. You would first need to register to the MasterCard Developer Zone, which will allow you then to register to one of the services available, among them, the ATM Locations web service.
The SDK is available for the Java language and provided that you properly set the authorization header in the HTTP request, getting ATM locations for a particular region seems to be relatively easy:
https://api.mastercard.com/atms/v1/atm?Format=XML&PageOffset=0&PageLength=10&AddressLine1=70 Main St&PostalCode=63366&Country=USA
There also seems to be a Visa Developer Program, with an ATM Locator Service available, but registration and access to the service is subject to Visa approval, see:
If you are not a Visa client, you will be contacted to determine
whether you are eligible to use the API. Your participation and access
to the API is subject to Visa approval.
Note that both of these SDK's are not that much Open Data, but they could be useful in case you do not get enough information with the Overpass API, or the Google Places API, respectively mentioned by @odjo and @FreshPrinceOfSO.