One of the concessions CMS made to the provider community last year in an attempt to quell anymore calls for further ICD-10 compliance date delays was to provide a one year grace period from claims rejection if the ICD-10 filed on the claim was not coded to the highest specificity. That did not mean the provider could just slap on any diagnosis code (e.g. a generic diabetes diagnosis when the patient presented w/a stubbed toe and was not diabetic) as the provider still had to have accurate medical documentation from the encounter. The provider had to be w/in the family of codes. For instance, in the above diabetes example, the provider could possibly code w/in the diabetes category (the first three digits of the diagnosis code) but not drill down to the most specific code based on the encounter.
The one year grace period is coming to an end. CMS has announced an update to the Q&A where they announced the coding flexibility last year. There is no leeway on extending this.
Read more here.