FREE ICD-10 Lookup
You can enter a diagnosis like "fibromyalgia" or a simple category such as "pain" and get a full list of current ICD-10 codes. Once you get the list you can choose a "mapping" option which will compare the chosen ICD-10 codes to current ICD-9 codes as well to help you understand if you've translated the code appropriately.
ICD-10 codes are much more complicated than ICD-9. In physical medicine, for instance, the 7 digit codes include not only coding for the affected body part and type of pain/injury but also whether it is an initial treatment or follow up treatment for the injury so it is important to understand the coding language and sequence enough to choose correctly.
Still, for a quick way to just get the numbers and start translating what you have in ICD-9 to an initial subset of ICD-10 codes, this is a great free resource.
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If you want a pared down set of codes specific to your profession, this is a good resource and still a comprehensive list.