The revenue cycle, in plain English.

The 270 asks a payer whether a patient's coverage is active and what it pays for; the 271 answers with the plan, network status, deductible, copay and coinsurance.

The 276 asks a payer where a claim stands, and the 277 answers: pending, finalized and paid, denied, or waiting for more information. It replaces most status calls.

The 277CA is the claim-level acknowledgment: for each claim in a batch, it says whether the clearinghouse or payer accepted it into processing or rejected it, and why.

The X12 278 is the electronic prior authorization transaction: the provider's request for approval of a service, and the payer's response with a decision and an authorization number.

The 837 is the standard electronic claim. 837P carries professional claims (the CMS-1500), 837I institutional claims (the UB-04), and 837D dental claims.

The X12 999 is the first response to a batch of electronic claims. It says whether the file passed format and implementation guide checks: accepted, accepted with errors, or rejected.

A Claim Adjustment Reason Code explains why a payer paid a claim line differently from what was billed. Paired with a group code (CO, PR, OA or PI), it accounts for every dollar not paid.

CO-4 means the procedure code doesn't fit the modifier used, or a required modifier is missing. It's a coding denial that a corrected claim usually fixes.

CO-11 means the payer found the diagnosis on the claim doesn't support the procedure billed, for example a knee diagnosis on a shoulder procedure.

CO-16 means the claim lacks information or has a billing error. A remark code always says what's missing, and the fix is usually a corrected claim.

CO-22 means the payer believes another insurer should pay first under coordination of benefits. The claim has to go to the primary payer, or the payer's records have to be corrected.

CO-27 means the service happened after the patient's coverage ended. The fix is finding the coverage that was active on the date of service.

CO-50 means the payer decided the service wasn't medically necessary under its policy. The provider can't bill the patient unless the patient signed a valid advance notice.

CO-97 means the payer considers the service included in another service it already paid, so it pays nothing extra. It's the classic bundling denial.

CO-109 means the claim went to a payer that doesn't cover the service and must be sent to the correct payer or contractor, such as a different Medicare jurisdiction or a managed care plan.

CO-150 means the payer decided the documentation doesn't support the level of service billed, often a higher-level office visit. The payer may pay a lower level or nothing.

CO-167 means the payer doesn't cover the service for the diagnosis billed. It's a coverage decision about the diagnosis, often driven by a coverage policy.

CO-197 means the payer denied the service because a required prior authorization, precertification or notification wasn't on file. The provider can't bill the patient for it.

CO-198 means an authorization existed, but the service went beyond it: more units or visits, a longer period, or a different service than the payer approved.

CO-236 means two procedures billed for the same day aren't allowed together under the National Correct Coding Initiative or a similar rule set, unless a modifier shows they were truly separate.

N54 is a remark code meaning the claim doesn't match what was authorized: a different code, number of units, date range or provider from the approval on file.

A Remittance Advice Remark Code adds detail to an adjustment: which information was missing, which policy was applied, or what to do next. It travels alongside a CARC.

Coordination of benefits decides which insurer pays first when a patient has more than one plan, so the claims go in the right order and nobody pays twice.

Eligibility verification confirms, before a service, that the patient's insurance is active and what it covers: the plan, network status, deductible, copay and coinsurance.

Insurance discovery searches for coverage a patient didn't mention or that replaced their old plan, by checking the patient's details against other payers.

Prior authorization is the payer's approval, before a service, that it will cover it. Without one, a service that needs it is denied, usually as CO-197.

Qualified Medicare Beneficiaries are low-income Medicare patients whose premiums and cost sharing Medicaid covers. Federal law bars providers from billing them for Medicare deductibles, coinsurance or copays.

An appeal asks the payer to reconsider a denial or reduced payment, with an argument and evidence. Each payer has levels and deadlines, and Medicare has five levels.

Claim scrubbing checks a claim against payer, coding and data rules before it's sent, so errors are fixed while they're cheap instead of coming back as rejections and denials.

A clearinghouse is the middle layer between providers and payers. It checks claims, routes them to the right payer, and passes back acknowledgments, status responses and remittances.

A corrected claim replaces a claim the payer already processed, fixing an error such as a code, modifier or missing number. It's sent with frequency code 7 and the payer's original claim number.

A redetermination is the first level of a Medicare Part A or B appeal, decided by the Medicare Administrative Contractor that processed the claim. It must be filed within 120 days.

A secondary claim bills a patient's second insurer for what the primary didn't pay, with the primary's payment details attached. Medicare often sends it automatically as a crossover.

Timely filing is the payer's deadline for receiving a claim, counted from the date of service. Miss it and the payer can deny the claim with CO-29, and the provider usually can't bill the patient.

A write-off removes a balance the provider won't collect, with an adjustment code that records why: a contractual amount, a small balance, a missed deadline or an exhausted appeal.

BAI2 is a standard bank statement file format. It lists every deposit and withdrawal with its details, including the trace numbers needed to match payer EFTs to their remittances.

A credit balance means more was paid on an account than was owed, by a payer, a patient or both. It usually has to be refunded, and Medicare overpayments must be returned within 60 days of being identified.

An EFT is a payer's electronic payment into the provider's bank account, sent by ACH with a trace number that links it to its ERA.

An Explanation of Benefits is the payer's statement of how it processed a claim: what was billed, what it allowed, what it paid, and what the patient owes.

An Electronic Remittance Advice, the X12 835, is the payer's electronic explanation of a payment: every claim and service line it covers, what was paid, and why the rest wasn't.

A fee schedule lists what a payer pays for each procedure code. Medicare publishes its own; commercial contracts set rates directly or as a percentage of Medicare.

A lockbox is a bank service that receives a provider's mailed payments, deposits the checks and scans the EOBs and correspondence, so paper payments arrive as images and data files.

Patient responsibility is the part of a claim the patient owes under their plan: the deductible, coinsurance and copay, reported on the remittance with group code PR.

The PLB segment of an 835 holds money that isn't tied to a single claim line: recoupments, interest, forwarding balances and other provider-level adjustments. It's why a payment can differ from the sum of its claims.

Prompt-pay laws require payers to pay clean claims within a set time, and to add interest when they're late. The interest is often owed but never paid unless someone asks.

A recoupment is a payer taking back money it says it overpaid, by deducting it from later payments instead of asking for a refund. It appears as a takeback or a PLB adjustment on a remittance.

Sequestration is a 2% across-the-board cut to Medicare fee-for-service payments, applied after the allowed amount is set and reported with adjustment code CO-253.

Unapplied cash is money received but not yet posted to a specific claim or patient, because the remittance is missing or the payment can't be matched. It keeps the deposit balanced while it's researched.

An underpayment is a claim paid below what the provider's contract says it should pay. It looks like a normal payment on the remittance, so most go unnoticed.

Coverage determinations are Medicare's written rules for when a service is reasonable and necessary. NCDs apply nationwide; LCDs are set by each Medicare Administrative Contractor for its region.

A service is medically necessary when it's reasonable and needed to diagnose or treat the patient's condition, as defined by the payer's policy. Services that don't meet it are denied, usually as CO-50.

A Medically Unlikely Edit is the most units of a service a provider would normally report for one patient on one day. Units above it are denied.

The National Correct Coding Initiative is CMS's set of coding edits that stops pairs of procedures from being paid together when one is part of the other, and limits units per service.

The No Surprises Act protects patients from surprise out-of-network bills, requires good faith estimates for uninsured and self-pay patients, and sends payer and provider payment disputes to independent dispute resolution.

The National Provider Identifier is the 10-digit number that identifies every healthcare provider in claims and other HIPAA transactions: Type 1 for individuals, Type 2 for organizations.

The TIN identifies the business entity that gets paid. Payers pay claims to a TIN, usually an employer identification number, which must match the billing provider's enrollment.

A/R aging sorts unpaid balances by how long they've been outstanding, usually in 30-day buckets. Older money is harder to collect, so the oldest buckets show where revenue is at risk.

Bank reconciliation matches every deposit in the bank account to the remittance or payment it came from, so the money posted in the billing system equals the money actually received.

The clean claim rate is the share of claims accepted on the first submission, without rejections, edits or manual fixes. It measures how well the front end and billing prepare claims.

Days in A/R measures how long it takes, on average, to collect revenue: net accounts receivable divided by average daily net revenue. Lower means faster cash.

The denial rate is the share of claims, or dollars, that payers deny on first processing. It's one of the clearest measures of how much revenue is at risk.

Month-end close is the checklist that ends a financial period: every remittance posted or explained, the bank reconciled, credit balances and unapplied cash reviewed, then sign-off and a locked period.

Revenue cycle management is everything between a patient's first contact and the last dollar collected: intake, eligibility, authorization, claims, payment posting, denials, underpayments and reconciliation.