Medical billing glossary

Every code and word we explain, in one place. Open one to see what it means, what it usually costs, and what to watch for.

105 terms

Billing and insurance words 40 terms

The words that show up on bills, EOBs, and denial letters.

Allowed amountThe allowed amount is the price your plan and the provider settled on for a service. It is the…
AppealAn appeal is a formal request for your plan to look at a denied claim again. The first round…
Balance billingBalance billing is when a provider bills you for the part of their charge your insurance did…
Billed charges (the hospital's list price)Billed charges are the provider's own list prices, taken from an internal price list that…
Billing modifierA modifier is a short add-on attached to a procedure code that says something about the…
ClaimA claim is the bill the provider sends to your insurance, not to you. It carries the dates of…
Claim denialA claim denial is your plan refusing to pay a claim, with a reason code saying why. Most…
CoinsuranceCoinsurance is your share of a covered service written as a share of the allowed amount…
Contractual adjustmentA contractual adjustment is the part of the charge the provider agreed to drop because of…
Coordination of benefitsCoordination of benefits is how two plans decide which one pays first when you are covered…
CopayA copay is a flat amount you pay for a covered visit, test, or prescription, set by your plan…
Date of serviceThe date of service is the day care actually happened, which is not the day the bill was…
DeductibleYour deductible is the amount of covered care you pay yourself each plan year before the plan…
Duplicate chargeA duplicate charge is the same service billed twice. It is usually process rather than intent…
Explanation of Benefits (EOB)An EOB is the letter or PDF your health plan sends after a provider files a claim for your…
External reviewExternal review is the step after your plan's internal appeal runs out: an independent…
Facility feeA facility fee is the hospital's charge for the room, the equipment, and the staff who are not…
Financial assistance (charity care)Financial assistance, sometimes called charity care, is a hospital program that reduces or…
Good faith estimateA good faith estimate is a written price estimate for scheduled care, meant for people who are…
In-networkIn-network means the provider signed a contract with your plan and agreed to accept the plan's…
Itemized billAn itemized bill is the line-by-line version of your statement: every service and supply with…
Medical debt in collectionsAn unpaid medical balance can be handed or sold to a collection agency, which then contacts…
Medical necessityMedical necessity is the test a plan applies when deciding whether to pay: did the care meet…
No Surprises ActThe No Surprises Act is a federal law that took effect in 2022. It deals with certain…
Non-covered chargeA non-covered charge is a line your plan refused to pay for and pushed onto you. The reason…
Observation statusObservation status means the hospital kept you in a bed, ran tests, and watched you overnight…
Out-of-networkOut-of-network means the provider has no contract with your plan. The plan either pays nothing…
Out-of-pocket maximumThe out-of-pocket maximum is the ceiling on what you pay for covered, in-network care in a…
Patient responsibilityPatient responsibility is the line at the bottom of the EOB where your plan adds up what it…
Payment planA payment plan spreads a balance over months instead of changing it. Hospital plans are often…
PremiumYour premium is what you pay to keep the coverage itself, usually every month and usually…
Preventive visit billed as an office visitMost plans cover in-network preventive care — the annual checkup, standard screenings — with…
Prior authorizationPrior authorization is your plan's approval, obtained before certain care happens, that the…
Professional feeA professional fee is the doctor's own charge for their work: examining you, performing the…
Revenue codeA revenue code is the short number on a hospital claim that says which department a charge…
Self-pay or cash priceThe self-pay or cash price is what a provider charges someone paying without insurance, and it…
Surprise billingA surprise bill is what people call a charge from a provider they never had the chance to…
Timely filingTimely filing is the deadline a provider has to send a claim to your plan, set by their…
UnbundlingUnbundling is billing the parts of a procedure as separate lines when the payment rules treat…
UpcodingUpcoding is billing a code that pays more than the care actually delivered supports — a brief…

Procedure codes (CPT) 40 terms

The five-digit codes a hospital or doctor puts next to each service on your bill.

CPT code 10060This is the charge for draining an abscess or infected pocket: the doctor numbs the area…
CPT code 12001This is the charge for closing a small cut with stitches, staples, or glue — the kind where…
CPT code 12002This is the next tier up for a straightforward stitch-up: a cut roughly one to three inches…
CPT code 29125This is the charge for putting a splint on your forearm or wrist — the rigid support that…
CPT code 36415This is the charge for drawing your blood — the needle stick itself, not the tests run on the…
CPT code 70450This is a CT scan of your head done without contrast dye, the standard scan after a head…
CPT code 71045This is the charge for a chest x-ray taken from one angle: the quick picture of your lungs and…
CPT code 71046This is a chest x-ray taken from two angles instead of one, usually front and side. The number…
CPT code 74177This is a CT scan covering both your belly and your pelvis, done with contrast dye. It is the…
CPT code 76705This is an ultrasound of part of your belly, usually aimed at one organ such as the…
CPT code 80048This is the basic chemistry panel: a fixed group of common blood tests, including kidney…
CPT code 80053This is the larger chemistry panel: everything in the basic one plus liver values and protein…
CPT code 80305This is the screening urine drug test, the one that returns a yes or no on classes of drugs…
CPT code 81001This is a urine test that includes someone looking at the sample under a microscope on top of…
CPT code 81003This is a urine test read by a machine: the dipstick strip that checks for things like blood…
CPT code 81025This is the quick urine pregnancy test that most emergency rooms run before x-rays, CT scans…
CPT code 82055This is the blood test that measures alcohol level. Emergency rooms order it after falls, car…
CPT code 83690This blood test checks the pancreas and is standard for pain in the upper belly. It is…
CPT code 83880This blood test measures a hormone your heart releases when it is under strain, and it is…
CPT code 84484Troponin is the blood test for heart muscle damage, and it is the reason chest pain visits…
CPT code 85025This is the standard blood count: red cells, white cells, and platelets, along with a…
CPT code 85610This blood test measures how quickly your blood clots, and it is standard for anyone on a…
CPT code 87635This is the lab-run COVID test, the one processed by a machine rather than the strip that…
CPT code 87804This is the quick nasal swab for influenza, read on the spot rather than sent to a lab. Each…
CPT code 87880This is the quick throat swab for strep, the one read in minutes in the department instead of…
CPT code 93000This is the all-in-one charge for an EKG: the heart tracing itself plus a doctor reading it…
CPT code 93005This is the hospital's half of an EKG: sticking on the leads, running the tracing, and…
CPT code 93010This is the doctor's half of an EKG: reading the tracing and writing the interpretation, with…
CPT code 94640This is the charge for a breathing treatment: medicine turned into a mist you breathe through…
CPT code 96360This is the line for plain fluids run into your vein — the bag of saline, not medicine. It is…
CPT code 96361This add-on stands for each extra hour of plain fluids after the first one. If you see three…
CPT code 96372This is the charge for giving you a shot — medicine pushed into a muscle or under the skin…
CPT code 96374This is the charge for a drug pushed straight into your vein through the IV all at once…
CPT code 99281Hospitals sort every emergency room visit into five levels, and 99281 is the lowest one. It…
CPT code 99282This is level 2 of the five levels a hospital uses to bill an emergency room visit, one step…
CPT code 99283Level 3 is the middle of the five levels used to bill an emergency room visit, and it is one…
CPT code 99284CPT 99284 is level 4 of the five levels hospitals use to bill an emergency room visit — the…
CPT code 9928599285 is the top of the five levels for an emergency room visit. The hospital is saying your…
CPT code 99291Critical care is billed by the clock, and this code covers the first block of it — roughly the…
CPT code 99292This line is the add-on for critical care that ran past the first block. Each one stands for…

Denial and adjustment codes 25 terms

The codes an insurer prints next to a line it did not pay in full, like CO-45 or PR-204.

Denial code CO-4CO-4 is a coding mismatch: the service code and the short flag attached to it, called a…
Denial code CO-11CO-11 means the reason recorded on the claim does not fit the service that was billed. Every…
Denial code CO-16CO-16 is the plan saying it cannot finish the claim as it was sent, because something it needs…
Denial code CO-18CO-18 means the plan is looking at a claim it believes it has already handled: same patient…
Denial code CO-29CO-29 means the claim reached the plan after the window the plan gives providers for sending…
Denial code CO-45CO-45 is the line where your plan cuts the provider's charge down to the price it will…
Denial code CO-50CO-50 means the plan decided this service does not meet its own rules for payment, given the…
Denial code CO-59CO-59 means more than one procedure happened in the same session and the plan applied its rule…
Denial code CO-97CO-97 means the plan already paid for this line inside another line on the same claim. Payment…
Denial code CO-109CO-109 means the claim went to a plan that is not the one on the hook for it. The plan is not…
Denial code CO-151CO-151 means the plan paid for part of what was billed but not all of it, because the number…
Denial code CO-234CO-234 means the plan does not pay this line on its own, because whatever it covers is meant…
Denial code CO-B7CO-B7 means the plan's records show this provider was not set up to be paid for this service…
Denial code OA-22OA-22 means the plan thinks somebody else should look at this claim first: another health…
Denial code OA-23OA-23 shows up when more than one plan is involved: it carries over what the first plan…
Denial code PI-24PI-24 means the plan is treating this care as already covered by a monthly arrangement it pays…
Denial code PR-1PR-1 is the part of the allowed amount that went toward your deductible, the covered care you…
Denial code PR-2PR-2 is your coinsurance: the share of the allowed amount the plan says is yours once the…
Denial code PR-3PR-3 is your copay: the flat amount your plan sets for a visit of this type. Your benefits…
Denial code PR-27PR-27 means the plan looked at the claim and found its coverage had already ended by the date…
Denial code PR-31PR-31 means the plan could not match the person on the claim to anybody it covers. Most of the…
Denial code PR-49PR-49 means the plan processed the visit as a routine or screening service that your benefits…
Denial code PR-96PR-96 means the plan is not paying for this line and is pointing the amount at you. It is a…
Denial code PR-119PR-119 means you have used up what the plan covers for this kind of care in the period it…
Denial code PR-204PR-204 means the service, drug, or item is not part of what your plan covers at all, and the…

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Written by us in plain English. We describe codes in our own words and never publish official code-book descriptions.

Educational information only — not legal, medical, or financial advice. Always confirm the details with your provider or insurer.