LetterAgent
Mail physical letters by just asking your AI assistant.
Home > Guides > Why dentists still fax
They fax because their insurance workflow is built on it. Predetermination requests, eligibility checks, claim attachments, and referral packets all travel by fax in dental offices, because the payers still publish dedicated fax lines and the paper trail settles disputes about what was sent and when.
| What goes by fax | Why fax, not email |
|---|---|
| Predetermination (pre-treatment estimate) requests | Payers publish fax lines for them and return written estimates the same way |
| Eligibility and benefits verification | Some carriers run automated "faxback" systems: the office dials in, keys the patient ID, and a benefits snapshot faxes back immediately |
| Claim attachments: X-rays, charts, narratives | The ADA claim form assumes attachments travel with the claim; fax keeps the whole packet together |
| Specialist referrals and prior authorizations | DHMO plans often require authorization before the visit; fax delivers the request and the paper confirmation |
| Appeals of denied claims | The confirmation page is timestamped proof the appeal went out before the deadline |
The honest answer is that every side of the transaction already agreed on fax decades ago, and nobody wants to be the first to break the agreement. Dental plans print fax numbers on their provider portals and claim forms. Practice software has "print and fax" buttons baked in. The front desk knows the drill. Switching to a portal means retraining staff, reconfiguring software, and hoping the payer's portal works that day, all to replace something that already works.
There is also a documentation argument that is not just habit. One dental billing services guide puts it plainly: fax gives you the documentation, the who and the when, even if it does not give you the full picture. A faxed predetermination comes back with a date stamp and an estimate attached, and if the payer later pays less than estimated, the office can point to exactly what the payer said and when. Email can do this too, but the fax confirmation page is a one-page artifact that billing staff can staple to the claim file and pull out in seconds during an appeal.
A predetermination (sometimes called a pre-estimate) is a written estimate the office requests from the plan before treatment starts: is this crown likely covered, and roughly how much will the plan pay? The ADA is careful to separate it from preauthorization: a predetermination is voluntary on most plans and never a guarantee of payment. Benefits are decided on the date of service, so if the patient loses coverage or exhausts the annual maximum between the estimate and the appointment, the numbers change.
This is exactly why the paper trail matters so much to dental offices. Patients who were quoted a confident number and then billed something different tend to blame the practice, not the plan. The office that can show the faxed estimate, the date it came back, and the limits printed on it has a much easier conversation than the office working from memory.
Slowly. Electronic claim attachments and payer portals exist, and larger group practices use them. But dental care in the US and Canada is still mostly small independent practices with a front desk of two or three people, and for them the fax machine is the lowest-friction route to every payer. As long as plans keep publishing fax lines and accepting faxed predeterminations, the machines are staying.
One thing to watch: some carriers now treat fax as the backup rather than the primary channel. If your dentist's office asks you to confirm a fax arrived, that is a sign the payer's side of the line is getting less attention than it used to. It does not mean fax is dead in dental. It means the confirmation page is doing more work than it used to.
Ready to fax it? Fax with LetterAgent: describe it to your AI assistant, approve the exact quoted price, and it is sent.
LetterAgent is a working name. Prices include print, postage, and our service fee. US prices in USD, Canadian prices in CAD (Canadian prices exclude applicable sales tax, added at checkout). Currently in private testing.
Need help? Ask your assistant: it can check a job's status any time. If it ever can't handle something: hello@getletteragent.com