The big unknown here is simply "what degree of specificity will payors require."
Neither the government nor any private payor has tipped their hand here. It will be impossible to "crosswalk" reliably, because ICD-10 is inherently more specific.
If payors allow non-specific codes -- at least in the beginning-- this might work, but there is enormous latitude for claim denial and misunderstanding (read cash flow disruption) unless this whole thing gets a lot more transparent pretty quick
