Crosscheck
Crosscheck support
Last updated 15 September 2026.
Crosscheck compares a medical bill against the Explanation of Benefits your insurer sent for the same care, shows you where the two disagree, and writes a letter that you send.
What the findings mean
You type the figures in. There is no text recognition, and nothing about your documents is photographed or uploaded. Everything reported is arithmetic between the two documents, ordered by money, and labelled either as subtraction between them or as something worth asking about.
- Billed above the EOB. The provider is asking for more than the insurer said you owe, which is the commonest real problem.
- Lines do not sum. The itemisation and the total disagree.
- Duplicate line. The same code, date and amount. All three, because fewer fields produce nonsense about legitimate repeat visits.
- EOB arithmetic. Allowed minus paid does not equal your share, by the insurer's own numbers.
- Service date mismatch. The documents may describe different visits.
Differences of a cent or two are ignored: that is rounding in somebody's billing system rather than a dispute.
Nothing was found. Is my bill correct?
Crosscheck cannot tell you that, and it does not say it. It says the smaller, true thing: the numbers you entered line up with each other. Plenty of billing problems never show up that way, so if something still feels wrong, ring the billing office. A finding is not a verdict either: nothing here means you do not owe the money.
Why it does not check the codes
There is no procedure code knowledge in this app. Upcoding, unbundling and medical necessity all need somebody who knows the code set, and being wrong about them sends a patient into a fight they lose while believing they are right. Crosscheck does the arithmetic you could check yourself in thirty seconds and nothing else: no statute, no claim of entitlement, no judgement about your care.
Why you send the letter, not us
Crosscheck writes three kinds of letter: to the billing office, a request for an itemised bill, and one to your insurer asking it to look again. Each opens in your own email or is shared from your device. We do not send it, and we are not copied on it. That keeps it a document you wrote rather than a case somebody is running for you. Crosscheck is not a lawyer and not a billing advocate, and nothing it produces is legal advice.
Every sentence it writes is a fact from your documents, a question or a request. If one ever reads as a legal claim it refuses to show that letter and says so, which is our bug rather than yours.
The paragraph you write yourself
There is a field for why you believe something should have been covered, and what you put there goes into the letter untouched. Your own words are never softened or policed, however legal they sound. The app cannot know your plan or your circumstances, and a guess is the thing it avoids.
Deadlines
Appeals usually have a deadline, often shorter than people expect. Your Explanation of Benefits normally states it, and the number on the back of your insurance card can tell you. Check it before anything else, because it is the one part that cannot be fixed later. Crosscheck does not track it for you.
Signing in, and what is stored
Signing in is by a code emailed to you, and there is no password. What is kept is your email address, each case, meaning the figures you entered and the differences worked out from them, and each letter composed for you. No member number, policy number or card details are asked for, and every table checks the signed in account against the owner of the row.
Deleting your account
From the Account tab. It removes your profile, every bill and every letter, for good. Save any letter you still need first. Letters you already sent are with the provider or insurer and are unaffected; we only ever had the draft.
Privacy
The full policy is at carrierpress.com/crosscheck/privacy. Supabase hosts the database and sends the sign in codes. No part of your case goes to a language model, another company, or advertisers.
Contact
One person reads that, so a reply may take a few days.
Crosscheck is published by Jeffrey L Carrier.