At present, the FHIR IG Publisher does not support directly referencing value sets in VSAC or PHINVADs. In principle this is no problem, but in practice, there are a series of issues since these sources require per-user access. The workaround has been to reproduce them in the IG. See:  https://chat.fhir.org/#narrow/stream/179252-IG-creation/topic/are.20we.20able.20to.20point.20to.20VSAC.20for.20bindings.3F That said, mCODE doesn't actually use the Elixhauser Comorbidity Index, but asks for reporting of any comorbid conditions that are considered in the ECI, as represented by the value set:  http://hl7.org/fhir/us/mcode/2019Sep/ValueSet-obf-ComorbidConditionVS.html , which includes the following concept codes: Includes codes descending from SCT#42343007 "Congestive heart failure (disorder)" Includes codes descending from SCT#698247007 "Cardiac arrhythmia (disorder)" Includes codes descending from SCT#368009 "Heart valve disorder (disorder)" Includes codes descending from SCT#39785005 "Disorder of pulmonary circulation (disorder)" Includes codes descending from SCT#400047006 "Peripheral vascular disease (disorder)" Includes codes descending from SCT#38341003 "Hypertensive disorder, systemic arterial (disorder)" Includes codes descending from SCT#44695005 "Paralysis (finding)" Includes codes descending from SCT#118940003 "Disorder of nervous system (disorder)" Includes codes descending from SCT#413839001 "Chronic lung disease (disorder)" Includes codes descending from SCT#73211009 "Diabetes mellitus (disorder)" Includes codes descending from SCT#40930008 "Hypothyroidism (disorder)" Includes codes descending from SCT#42399005 "Renal failure syndrome (disorder)" Includes codes descending from SCT#235856003 "Disorder of liver (disorder)" Includes codes descending from SCT#13200003 "Peptic ulcer (disorder)" Includes codes descending from SCT#86406008 "Human immunodeficiency virus infection (disorder)" Includes codes descending from SCT#3723001 "Arthritis (disorder)" Includes codes descending from SCT#64779008 "Blood coagulation disorder (disorder)" Includes codes descending from SCT#414916001 "Obesity (disorder)" Includes codes descending from SCT#89362005 "Weight loss (finding)" Includes codes descending from SCT#237840007 "Disorder of electrolytes (disorder)" Includes codes descending from SCT#271737000 "Anemia (disorder)" Includes codes descending from SCT#15167005 "Alcohol abuse (disorder)" Includes codes descending from SCT#66214007 "Substance abuse (disorder)" Includes codes descending from SCT#69322001 "Psychotic disorder (disorder)" Includes codes descending from SCT#35489007 "Depressive disorder (disorder)" Proposed resolution: Not persuasive