If you own Dragon Medical Practice Edition version 15 and are experiencing issues with vocabulary and corrections, you may want to consider upgrading to the Professional edition.
The Dragon Medical Practice Edition 4 (Professional) does include access to a medical vocabulary and offers more advanced features than the Practice Edition, including the ability to import and export custom vocabularies. Additionally, the Professional edition may offer better performance and accuracy than the Practice edition.
As for the upgrade process, it may depend on your specific situation and the policies of the software vendor. Some vendors may offer a discounted upgrade price for users of the Practice Edition who want to upgrade to the Professional edition, while others may require you to purchase the Professional edition at full price.
To find out more about the upgrade process and pricing options for Dragon Medical Practice Edition, you can check with the software vendor or reseller from whom you purchased the software. They should be able to provide you with more information on the available upgrade options and any associated costs.