A surgeon who owns her practice told us she had been nodding through the monthly billing meeting for six years. She knew what a denial was. She did not know the difference between a rejection and a denial, why "days in AR" was 38 when patients paid at the visit, or why her biller kept saying "the adjustment" as if there were only one. She is a careful, numerate person. Nobody had ever handed her the vocabulary.
This is the list of medical billing terms every physician should know, written for someone who runs a practice and wants to understand the reports without becoming a biller. We have grouped the terms by where they appear in the flow of a claim, from the front desk to the bank, because the order helps them stick. For each term we give the plain meaning, the number you should be watching if there is one, and the way the term gets misused, because the misuse is usually where the money disappears.
Read it once, then keep it next to the monthly report. When a word in the report isn't on this page, ask the biller to define it before the meeting moves on. That question, asked consistently, changes the quality of a practice's billing more than most software does.
Key takeaways
- Most billing confusion comes from a dozen terms that sound alike: charge, allowed, paid, adjusted, denied, rejected, written off.
- The physician's job is not to bill but to know which numbers should move and which direction.
- "Adjustment" is the word to interrogate hardest, because it hides both legitimate contract discounts and real losses.
- Every term on this list has a report behind it; ask to see the report, not just the summary line.
Medical billing terms every physician should know before the visit: coverage
Eligibility is whether the patient is covered by the plan on the date of service. It is checked electronically before the visit. Watch: the share of visits with a completed eligibility check, which should be near 100 percent. Misuse: "eligible" is often treated as "will pay," when it only means "has a policy."
Benefits are what the plan covers and what the patient owes: copay (a fixed amount per visit), deductible (the amount the patient pays before the plan pays anything in a plan year) and coinsurance (the percentage the patient pays after the deductible). Watch: the percentage of patient responsibility collected at the time of service. Misuse: staff say "the copay" when they mean the entire patient responsibility, and the deductible portion never gets asked for.
Prior authorization is the payer's advance approval for a service. Referral is the primary care physician's permission for a specialist visit in an HMO plan. They are different documents with different denial codes (CO-197 for a missing authorization, CO-15 or a payer-specific code for a missing referral). Misuse: treating them as interchangeable.
In-network means the practice has a contract with the plan and agrees to accept its allowed amount. Out-of-network means no contract; payment is usually lower and the patient may be balance-billed within the limits of state and federal law. Credentialing is the plan's verification of a provider's qualifications; contracting is the agreement on rates. A provider can be credentialed and not yet contracted, or the reverse.
After the visit: the claim words
Charge is the practice's list price for a service, set in the fee schedule (your prices) or the charge master (the same thing in a hospital). It is not what anyone pays. Allowed amount is what the payer agrees the service is worth under the contract, and it is the number that matters. Paid amount is what the payer actually sent, which is the allowed amount minus what the patient owes.
Contractual adjustment (or contractual write-off) is the difference between the charge and the allowed amount for an in-network payer. It is expected and unavoidable. Watch: whether the allowed amount matches the contract rate you loaded; when it doesn't, that's an underpayment. Misuse: this is where the word "adjustment" becomes dangerous. A real denial posted as a contractual adjustment vanishes forever.
Clean claim is a claim paid on the first submission with no rejection or denial. Rejection means the claim never entered the payer's system, usually a data or format error caught by the clearinghouse or payer front end. Denial means the payer processed the claim and refused payment, with a reason code on the remit. Watch: clean claim rate and denial rate, by payer. Misuse: vendors report the clearinghouse acceptance rate and call it the clean claim rate.
Clearinghouse is the intermediary that formats and routes claims to payers and returns remittances. Scrubber is the software that checks claims for errors before submission. Timely filing is the payer's deadline for receiving a claim after the date of service, from 90 days to a year depending on the contract; a claim filed late is denied with CO-29 and usually cannot be recovered.
The reading of the remit
Remittance advice, or ERA (electronic remittance advice, the 835 transaction), or EOB (explanation of benefits, the patient's version), is the payer's statement of what it paid and why. CARC (claim adjustment reason code) is the standardized reason for any unpaid amount; RARC (remittance advice remark code) is the detail. Group code says who owes the unpaid amount: CO for the provider, PR for the patient.
Payment posting is recording the remit against the claim in the practice system. Unapplied cash is money received and deposited but not yet matched to a claim. Watch: the unapplied balance at month end, which should be small and explained. Recoupment (or takeback) is the payer reclaiming a prior payment, often by reducing a later remit. Refund is money the practice returns because it was overpaid, and there are deadlines for returning it, sixty days for Medicare after the overpayment is identified.
| Term | Plain meaning | Number to watch |
|---|---|---|
| Days in AR | Average number of days between the date of service and payment for the money currently outstanding | Total AR divided by average daily charges; most practices aim below 35 to 40 |
| AR over 90 days | Share of outstanding balances older than 90 days | Percentage of total AR; the older it is, the less collectible |
| Net collection rate | What you collected as a share of what you were entitled to collect after contractual adjustments | Payments divided by (charges minus contractual adjustments); mid-to-high 90s is healthy |
| Gross collection rate | Payments as a share of charges | Mostly meaningless because charges are arbitrary; ignore it |
| Denial rate | Share of claims denied on first submission | By payer and by reason; the trend matters more than the level |
| Charge lag | Days between the date of service and the date the charge entered the system | Average days; anything over two or three is money sitting in the EHR |
| Bad debt | Patient balances written off as uncollectible | As a share of patient responsibility billed |
The words that describe your money
Accounts receivable (AR) is everything owed to the practice for services already delivered: by payers and by patients. It is broken into aging buckets (0 to 30 days, 31 to 60, 61 to 90, 91 to 120, over 120), and the older buckets are where the losses live. Days in AR is the average age of that money, and the surgeon's 38 days was normal, because most of a practice's revenue comes from payers that take three to six weeks to pay, regardless of what patients do at the desk.
Write-off is any balance removed from AR without payment. The contractual write-off is legitimate. A small balance write-off is a policy decision. A bad debt write-off is a patient balance you gave up on. An administrative write-off is the vaguest category and the one to audit, because it is where timely filing losses, unappealed denials and posting errors are buried. Watch: administrative write-offs by reason, monthly, in dollars.
Revenue leakage is the sum of all the money the practice earned and never collected: uncaptured charges, unappealed denials, underpayments, missed timely filing, uncollected patient balances. Our RCM audit exists to put a number on it, because most practices have never measured it and most physicians are surprised by the size.
The code words
CPT codes describe what was done (99214 is an office visit of moderate complexity). HCPCS Level II codes describe supplies, drugs and services CPT doesn't cover (G0439 is a Medicare wellness visit, J1100 is a drug). ICD-10-CM codes describe why (E11.9 is type 2 diabetes without complications). Modifiers adjust how a CPT code is paid (25 for a separate visit on a procedure day, 50 for bilateral). NCCI edits are Medicare's rules about which codes can be billed together. RVU (relative value unit) is the weight assigned to each code; multiplied by the conversion factor, it produces the Medicare fee.
Misuse in this section is about ownership. Physicians choose the CPT and ICD-10 codes, or approve the coder's choice, and the physician's signature is what a payer audits. "The biller picked the code" is not a defense, and a physician who knows what 99214 requires is protecting the practice, not doing the coder's job.
Questions we hear
Which three numbers should I look at every month if I only have five minutes?
Net collection rate, AR over 90 days as a percentage, and denials by reason for the top five reasons. Those three tell you whether you are collecting what you earned, whether old money is piling up, and where the work is.
My biller says our collections are "fine." How do I check?
Ask for the net collection rate and how it was calculated, then ask for the administrative write-off report by reason for the last three months. If either takes more than a day to produce, that is information too.
Is a low charge lag really that important?
Yes. Every day a charge sits unbilled is a day added to your cash cycle, and charges that sit too long fall off the edge into timely filing denials. It is also the metric the physician controls most directly, because it is usually the note that is late, not the biller.
What to do this week
- Print this glossary and bring it to the next billing meeting.
- Ask for the three reports named above: net collection rate, AR aging, denials by reason.
- Ask what the "adjustment" line on your monthly summary contains, category by category.
- Pick one term you didn't know and ask to see the report behind it.
- Agree with your billing lead on the five numbers you will review together every month, and their definitions.
