This is a cross post of the issue I opened with the validator here CMSgov/price-transparency-guide-validator#138
I am including it here because I intend to create a pull-request to revert the JSON Schema files from draft-07 to draft-04 and to re-write schema entries which are not supported by validator.
This issue was the cause of the "oneOf" "const" issue which was patched last week. It is also causing negative or zero rates to be accepted as "valid".