Definitely, the Pro/Premier/Accountant files are compatible as long as they are the same year or you are opening with a newer year.  (However, you can never go backwards with QB

Resolution for 'compatible as long issue: 'I have QB 2013 Premier and support ends in a couple of weeks. I don’t need Premier anymore. Can I “update” with Pro?' available: Yes.

The compatible as long issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the compatible as long issue yourself by looking for a resolution described in the article. If it is a complex compatible as long issue or you are unable to solve the issue, you may contact us by clicking here or by using other compatible as long support options.

For more information about resolving issues related to compatible as long in Quickbooks/QBO or to get support for the issue 'I have QB 2013 Premier and support ends in a couple of weeks. I don’t need Premier anymore. Can I “update” with Pro?', click the link below: