ANSI 837 (for sending claims), ANSI 835 (for recieving remittance), and ANSI 270/271 (for eligibility inquiries) are all government standards of data interchange.
The issue is that it takes a lot of work to send what all the different insurance companies are looking for. Many of the fields in the 837, for example, are situational so carrier A may need one or two of the fields but carrier B may not. In fact, if you include the fields carrier B does not want to see, carrier B will reject the claim even though it sounds like all they would have to do is ignore the field - but they don't.
A good clearinghouse takes care of all this for you through custom overrides and edits to make your claims go through.
The reason Office Ally is free is because the carriers pay Office Ally so they pass the total savings over to you. I keep hearing rumors that the carriers are going to stop paying clearinghouses, but those rumors thus far remain unfounded. Furthermore, the farther east you move, the more useless Office Ally becomes as they are based in CA and just don't have the relationships with the far east carriers.
Here is an example of what an 835 file looks like (the 837 is far, far more complicated than this):
ISA*00* *00* *ZZ*REALMED *ZZ*3884 *110608*1240*U*00401*023539370*0*P*>~
GS*HP*REALMED*3884*20110608*124057*651*X*004010X091A1~ST*835*651001~BPR*I*486.7*C*CHK************11111111~TRN*1*10020177*1560894904~
REF*EV*352091331~REF*F2*CLMA278DF1~DTM*405*20110606~N1*PR*BLUE CROSS BLUE SHIELD OF NORTH CAROLINA~N3*PO BOX 5555~N4*CITY*NC*277072219~
PER*CX*FEDERAL EMPLOYEE PROGRAM*TE*8002224739~N1*PE*CAPE MEDICAL *XX*1316999527~N3*ADDRESS ONE ~N4*CITY*NC*ZIP~
REF*TJ*561245721~LX*1~CLP*194011000811P*1*140*0*0*12*050511979660PM~NM1*QC*1*LASTNAME*FIRSTNAME*M***MI*R01613770~DTM*050*20110505~
DTM*232*20110328~DTM*233*20110328~SVC*HC>99202>25*80*0**1~DTM*472*20110328~CAS*OA*18*80~
REF*HPI*111111111~REF*6R*0001457~LQ*HE*M87~SVC*HC>11721*60*0**1~DTM*472*11111111~CAS*OA*18*60~REF*HPI*1124079256~REF*6R*0001458~
LQ*HE*M87~LX*2~CLP*109153003772S*1*40*0*40*12*060211931658PM~NM1*QC*1*LASTNAME*FIRSTNAME*M***MI*R01613945~DTM*050*20110602~
DTM*232*20110428~DTM*233*20110428~SVC*HC>11719>GY*40*0**1~DTM*472*20110428~CAS*PR*96*40~REF*HPI*1780634535~REF*6R*0015715~LQ*HE*N174~
LX*3~CLP*139268004802P*2*175*19.87*60*12*060311979076PM~NM1*QC*1*LASTNAME*FIRSTNAME*R***MI*R11690939~DTM*050*20110603~
DTM*232*20110509~DTM*233*20110509~SVC*HC>99203>25*115*19.87**1~DTM*472*20110509~CAS*CO*45*15.65**23*79.48~REF*HPI*1124079256~REF*6R*0024902~
AMT*B6*99.35~LQ*HE*MA04~LQ*HE*N381~SVC*HC>11721*60*0**1~DTM*472*20110509~CAS*PR*96*60~REF*HPI*1124079256~REF*6R*0024903~LQ*HE*N174~
LX*4~GE*3*651~IEA*1*023539370~
JamesNT
.png "ACUF Donor I")
