You’re not alone with this letter
Medical bill codes — what those letters and numbers mean
A medical bill or EOB is full of codes the billing system understands and you were never meant to memorize. Procedure codes (often CPT or HCPCS) describe the service. Remark or adjustment codes (PR, CO, OA plus a number) explain why a dollar amount moved. You need plain English for the lines on *your* page—not a codebook. Photo the statement.
Take a photo of every page
Phone camera, or a PDF from your portal. Free one-line preview. Full understand + respond pack $8 from your pages — checklist and a calm draft. We don’t sell your documents or contact your insurer. Educational only; not legal advice.
Photo the papers in your hand
Camera is fastest on a phone. A PDF from your insurer portal works too. Add every page (up to 10).
We don’t sell your documents, and we never contact your insurer or collector. Default keep is about 30 days.
Not ready to upload yours?
Open a full sample pack (free) — then photo your real letter for a custom one.
What’s in the full pack
- Plain English of the amounts, dates, and asks on your pages
- Who to contact and a short checklist for this situation
- Call and email scripts written from your letter
- For collection notices: a debt validation–style draft when it fits
Why a clear response matters
Ignoring a letter rarely helps. A calm written or phone reply — asking for verification, itemization, or a dispute in the window they gave you — often puts the sender on a process they have to follow, and leaves you with a paper trail. We help you take that first step without sounding lost.
Educational only — not legal advice. Rights and deadlines depend on the document and your situation.
The three families you usually see
They answer different questions.
- Procedure / service codes (CPT, HCPCS): what was billed — office visit, lab, imaging
- Diagnosis codes (ICD): the reason the plan was given for the visit
- Remark / adjustment codes (PR, CO, OA + a number): why the plan paid less than the charge, or why a balance is marked as yours
Remark codes people actually type
These sit next to the dollars. They are not the same as a CPT code.
- PR-1, PR-2, PR-3 — often deductible, coinsurance, or copay (the plan is saying this piece is patient responsibility)
- CO-45 — a contractual adjustment: the plan’s allowed amount is lower than the charge; that slice is usually not yours if the provider is in network
- OA or other two-letter prefixes — “other adjustment”; read the short description printed next to the code
If a code looks wrong
Ask the provider for an itemized bill and whether the code matches the service you received. For remark codes, compare the adjustment to your EOB. Don’t guess a CPT from memory—put the question in writing with the code copied exactly.
FAQ
- What is a medical bill code?
- Usually a procedure code (CPT/HCPCS) naming the service, or a remark/adjustment code explaining a dollar amount. Photo the line; you do not need to look it up yourself.
- What does CO-45 mean on an EOB?
- It is commonly a contractual adjustment—the difference between the billed charge and the plan’s allowed amount. In-network, that slice is often written off, not billed to you. Check the printed description and your contract status. Educational only.
- What does PR-1 mean?
- PR usually means patient responsibility. PR-1 is often deductible. The number next to it is what the plan assigned to you for that claim line—not always the same as the provider’s later bill.
Still holding the letter?
Take a picture of every page. Free preview first — unlock the full pack only if it helps.
Take a photo