Preauthorization and predetermination are not the same thing
A preauthorization asks a payer whether treatment may go ahead. A predetermination asks what the payer would pay if it did. They are different questions, they come back in different forms, and neither one is a guarantee that money will arrive, because both remain subject to the patient's eligibility on the day the treatment actually happens.
The difference in one paragraph
Both are a question you send a payer before doing the work, and both come back as a written response. The difference is what you asked. A preauthorization asks whether the payer agrees the treatment should be done at all, which matters on plans that require it before they will consider a claim. A predetermination asks the payer to look at the proposed treatment and say what it would pay toward it, which matters when the patient needs a number before agreeing.
What actually binds a payer
Less than most offices expect, and this is the part worth being precise about with patients.
- What an approval does
- It tells you the payer has looked at the proposed treatment and, on the information in front of it, considers it consistent with the plan. That is real and it is worth having, particularly where the plan requires it.
- What it does not do
- It does not promise payment. The claim is still adjudicated when it arrives, against the patient's eligibility, remaining annual maximum and any frequency limit, all as they stand on the date of service rather than the date of the approval.
- Why that gap exists
- Coverage is a moving thing. A patient can change employer, exhaust an annual maximum on other treatment, or have a plan year turn over between the approval and the appointment. None of that is the payer going back on its word.
The practical consequence is that an approval is a reason to proceed with confidence, not a reason to promise a patient a number. The safe sentence to a patient is that the plan has agreed the treatment is covered and here is what we expect it to pay, with the same caveat everyone gets: it depends on the benefit still being there on the day.
When each is worth requesting
Both cost time, and the time is the reason offices skip them and then get surprised. A useful rule is to spend the wait where the downside is largest.
- Request a preauthorization when the plan requires one. This is not optional and the claim will be declined without it. Knowing which of your payers require it, for which procedures, is a short list worth writing down once.
- Request a predetermination when the number will decide whether the patient proceeds. Larger treatment plans, crowns and above, anything where an unexpected balance would damage the relationship.
- Skip both for routine, clearly covered treatment. The wait costs the patient an appointment and buys nothing.
- Always verify eligibility separately. An approval is not an eligibility check, and eligibility is the thing most likely to have changed.
How long an approval lasts
Approvals expire. How long they last varies by payer and is stated on the response, and it is commonly a matter of months rather than years. The failure mode is not that offices do not know this; it is that the approval arrives, gets filed, the patient schedules for after a holiday, and nobody looks at the date again.
This is a genuinely expensive small problem. The treatment gets done, the claim goes out, and the payer declines it because the approval it references is no longer live. At that point the work is finished, the patient has an unexpected balance, and neither of those conversations is a good one.
Tracking them so none expires
- Record the expiry date, not the approval date. The approval date is the one the paperwork leads with and the one that does not matter.
- Keep an unscheduled list. Every approval where treatment has not yet been booked is a live risk. That list should be short and somebody should own it.
- Sort it by time remaining. Not by patient name, not by dollar value. The one closest to expiry is the one to call today.
- Re verify before treatment on anything old. If the approval has been sitting for months, an eligibility check the week before is cheaper than a declined claim after.
None of this needs a system. It needs a list that is current, which is the part that quietly stops happening in a busy month.
The short version
- A preauthorization asks permission; a predetermination asks for an estimate of payment.
- Neither is a payment guarantee, because both are still subject to eligibility and remaining benefit on the date of service.
- The words are used loosely, including by payers, so read what the response actually says rather than what it is called.
- Approvals expire, and an expired approval on treatment that has been scheduled for months is a preventable write off.
- Track them by expiry date, because the risk is not getting the answer, it is forgetting the answer had a shelf life.
Where this sits in Practice Evolved
Practice Evolved lists the approvals that have not yet been scheduled and how long each one has been sitting there, read out of your own practice software, so the list you have to check the expiry dates against is short and is in front of somebody.