List of HIPAA transactions:
| 270 | Eligibility Request |
| 271 | Eligibility Response |
| 275 | Claims Attachment |
| 276/277 | Claims Status Request and Response |
| 277 | Claim Request for Additional Information |
| 278 | Referral/Authorization Request and Response |
| 834 | Enrollment |
| 835 | Claim Payment/Advice |
| 837 | Dental (837-D), Institutional (837-I), Professional (837-P) Claims |
| NCPDP 5.1 | Pharmacy |
NPI = National Provider Identifier – a new unique identifier assigned to all providers. Current requirement is that by May 2009 all claims must contain this number. http://www.cms.hhs.gov/NationalProvIdentstand/