Informational Article
Medical Claims:
Process, Types, Challenges and How They Work
A medical claim is a standardized request for payment that a healthcare provider submits to an insurance payer, listing the patient, the provider, the diagnoses, the services performed, and the charges for those services. Medical claims work through a defined lifecycle: claim creation, scrubbing, submission through a clearinghouse, payer acknowledgment, adjudication, remittance, payment posting, and, where necessary, correction, appeal, secondary billing, or patient billing.
Medical claims are classified by format and by status. By format, the main types are professional claims (CMS-1500 and 837P), institutional claims (UB-04 and 837I), dental claims (ADA form and 837D), and pharmacy claims (NCPDP). By status, a claim can be clean, rejected, denied, pended, partially paid, corrected, or secondary.
Claim outcomes drive practice cash flow more than any other single factor. Industry data shows denial pressure rising year over year, with the 2025 Experian Health State of Claims survey reporting that 41 percent of surveyed providers experience denial rates of 10 percent or higher, compared with 30 percent in 2022. A large share of initially denied claims are ultimately paid after appeal, which means much of the loss is not caused by the denial itself but by claims that are never reworked before the filing deadline expires.
This guide explains what a medical claim contains, how the claim process works step by step, the difference between a rejection and a denial, the most common denial reasons, how to appeal, what timely filing means, and which metrics tell you whether your claims operation is healthy.
What Is a Medical Claim?
A medical claim is the formal billing document that tells an insurance payer what care was delivered, to whom, by whom, on what date, under what diagnosis, and at what charge. It is simultaneously a payment request, a medical necessity statement, and a legal attestation that the services listed were actually provided and documented.
Claims are submitted either electronically or on paper. Electronic claims dominate because they are faster, cheaper, trackable, and required by most payers. Paper claims survive in narrow situations, such as certain workers compensation, auto liability, or secondary claims that require attachments the payer cannot receive electronically.
What Are the Components of a Medical Claim?
The components of a medical claim are the identifying, clinical, and financial data elements the payer needs to adjudicate. Every one of these fields is a potential rejection point.
Patient and subscriber data: name, date of birth, gender, address, member ID, group number, and relationship to the subscriber.
Payer data: payer name, payer ID, plan type, and the primary or secondary sequence if more than one plan applies.
Provider data: rendering provider NPI, billing provider NPI and tax ID, taxonomy code, service facility address, and referring or ordering provider when required.
Encounter data: dates of service, place of service code, and admission and discharge information on institutional claims.
Diagnosis codes: ICD-10-CM codes establishing the reason for the encounter and supporting medical necessity.
Service lines: CPT or HCPCS codes with modifiers, units, diagnosis pointers, and charge amounts per line.
Authorization data: prior authorization number, referral number, and accident or injury information where applicable.
Institutional-specific data: revenue codes, type of bill, condition codes, occurrence codes, and value codes on the UB-04 and 837I.
How Does the Medical Claim Process Work?
The medical claim process works by building a complete and accurate claim, validating it before submission, transmitting it to the payer, tracking its acknowledgment and adjudication, posting the payer response, and resolving any unpaid balance through correction, appeal, secondary billing, or patient responsibility.
What Are the Types of Medical Claims?
Medical claims are classified by format, by submission method, and by status. A single claim can be described by all three at once, for example an electronic professional claim currently in denied status.
Types of Medical Claims by Format
Professional claim
Form: CMS-1500
Transaction: 837P
Submitted by: Physicians and individual practitioners
Institutional claim
Form: UB-04 (CMS-1450)
Transaction: 837I
Submitted by: Hospitals, SNFs, ASCs, home health, hospice
Dental claim
Form: ADA dental claim form
Transaction: 837D
Submitted by: Dental providers
Pharmacy claim
Form: NCPDP format
Transaction: NCPDP telecommunication standard
Submitted by: Retail and specialty pharmacies
Types of Medical Claims by Status
Clean claim
contains complete and accurate information and can be adjudicated without correction or additional documentation.
Rejected claim
failed a front-end format or data edit and never entered adjudication; it must be corrected and resubmitted, not appealed.
Denied claim
entered adjudication and was processed with a decision not to pay; it carries a claim number and formal appeal rights.
Pended or suspended claim
held by the payer pending records, coordination of benefits information, or manual review.
Partially paid claim
some lines paid, others denied or reduced, which requires line-level review rather than claim-level review.
Corrected claim
a resubmission that replaces a previously processed claim, marked with the appropriate frequency code and original claim reference.
Secondary or tertiary claim
billed to a subsequent payer with the prior payer remittance attached.
Void or cancel claim
withdraws a previously submitted claim from the payer system.
What Is the Difference Between a Claim Rejection and a Claim Denial?
The difference between a claim rejection and a claim denial is where the claim stopped. A rejection occurs before adjudication, at the clearinghouse or the payer front end, because of a format or data error. A denial occurs after adjudication, when the payer has processed the claim and decided not to pay all or part of it.
| Attribute | Claim Rejection | Claim Denial |
|---|---|---|
| Stage | RejectionBefore adjudication | DenialAfter adjudication |
| Cause | RejectionFormat, missing field, invalid ID or code | DenialCoverage, medical necessity, authorization, coding, or contract rules |
| Claim number issued | RejectionNo | DenialYes |
| Appeal rights | RejectionNone; correct and resubmit | DenialYes; reconsideration or formal appeal |
| Correct response | RejectionFix the data and resubmit as a new claim | DenialAnalyze the reason code, then correct, resubmit, or appeal |
| Typical turnaround | RejectionSame day to a few days | DenialWeeks, and longer through appeal levels |
Key insight: Treating a rejection as a denial wastes appeal effort on a claim the payer never received, and treating a denial as a rejection can trigger duplicate claim denials. Distinguishing the two correctly is one of the highest-leverage habits in a billing operation.
What Are the Most Common Reasons Medical Claims Are Denied?
The most common reasons medical claims are denied are eligibility problems, missing authorization, coding errors, missing documentation, timely filing lapses, coordination of benefits conflicts, duplicate submissions, non-covered services, and provider enrollment issues.
Coverage not in effect or patient not eligible on the date of service
usually preventable by verifying eligibility at every visit rather than at registration only.
Missing or invalid prior authorization
the service was covered but not approved before it was rendered, or was performed outside the approved date range or unit count.
Medical necessity not established
the diagnosis reported does not meet the payer coverage policy or local coverage determination for the procedure billed.
Coding errors
invalid, deleted, or unspecified codes, incorrect modifiers, bundling conflicts, or a diagnosis that does not support the procedure.
Missing documentation
the payer requested records, an operative report, or a certificate of medical necessity that was never supplied.
Timely filing exceeded
the claim was submitted after the payer deadline, which is generally not appealable without proof of timely original submission.
Coordination of benefits
the payer believes another plan is primary, or the member COB record on file is out of date.
Duplicate claim
the same service was submitted more than once without a corrected-claim indicator.
Non-covered service or benefit exhausted
the plan excludes the service, or the visit, unit, or annual maximum has been reached.
Provider not enrolled or out of network
credentialing lapses and network status problems make otherwise perfect claims unpayable.
Bundled or included in another service
the service falls within a global surgical period or another procedure allowance.
How Do You Appeal a Denied Medical Claim?
Appealing a denied medical claim requires identifying the exact denial reason, gathering evidence that contradicts it, and filing within the payer appeal window using the payer required format.
Read the remittance carefully and identify the specific claim adjustment reason code and remark code at line level, not claim level.
Determine whether the correct response is a corrected claim, a reconsideration request, or a formal appeal, because filing the wrong one restarts the clock.
Confirm the appeal deadline for that payer and that claim type, and calendar it immediately.
Assemble supporting evidence: chart notes, operative report, authorization number, eligibility verification record, proof of timely filing, medical policy citation, or contract language.
Write a short, specific appeal letter that states the claim details, the denial reason, why the denial is incorrect, and the exact resolution requested.
Submit through the payer required channel, whether portal, mail, or fax, and retain the confirmation.
Track the appeal in a worklist with a follow-up date, and escalate to the next appeal level or an external review if the response is unsatisfactory.
Feed the outcome back into front-end and coding processes so the same denial reason stops recurring.
What Are Timely Filing Limits for Medical Claims?
Timely filing limits are the deadlines by which a claim must be received by the payer to be considered for payment. They vary by payer, plan, state, and contract, and a claim submitted after the limit is generally written off with no appeal rights.
Medicare
generally allows a filing period of one calendar year from the date of service.
Medicaid
limits are set by each state and can be considerably shorter than Medicare.
Commercial payers
set limits by contract, and the same carrier can carry different limits across product lines.
Workers compensation and auto no-fault
carry some of the shortest windows and the strictest enforcement, and some are measured in weeks.
Secondary claims
usually have their own separate deadline running from the primary remittance date.
Best practice: Verify each limit in the current payer provider manual or contract before publishing, and maintain a written filing-deadline matrix for your own payer list. These deadlines change with contract renewals.
What Are the Challenges of Medical Claims Management?
The challenges of medical claims management are rising denial volume, payer policy variability, prior authorization burden, incomplete front-end data, staffing constraints, and limited visibility into claim status.
Rising denial volume
more claims denied means more rework capacity is required simply to hold collections flat.
Payer rule variability
the same service can require different modifiers, documentation, and authorization at three payers in one market.
Prior authorization burden
authorization volume consumes clinical and administrative time and delays care as well as payment.
Front-end data quality
most denials originate in registration and eligibility, not in the billing department that has to fix them.
Staffing constraints
billing turnover leaves aged A/R unworked, and unworked A/R ages past appeal and filing deadlines.
Fragmented technology
disconnected EHR, practice management, and clearinghouse systems hide missing charges and unposted remittances.
No denial analytics
without reason-code trending, a practice fixes individual claims forever instead of fixing the cause once.
How Can Practices Improve Claim Performance?
Improving claim performance means shifting effort from post-denial rework to pre-submission prevention, and measuring the result.
Clean claim rate
Measures: Share of claims accepted on first submission
Direct measure of front-end and coding accuracy
First-pass resolution rate
Measures: Share of claims paid without rework or appeal
Shows the true cost of your current process
Denial rate
Measures: Denied claims as a share of claims submitted
Tracked by payer and reason code to find root causes
Days in accounts receivable
Measures: Average days from service to payment
The clearest indicator of cash flow health
Aged A/R over 90 days
Measures: Share of balance past 90 days
Recovery odds drop sharply beyond this point
Net collection rate
Measures: Collected versus contractually collectible
Exposes preventable write-offs and underpayments
Appeal overturn rate
Measures: Share of appeals resulting in payment
Shows whether denials are truly valid or simply unchallenged
How EverCure Billing
Manages Medical Claims
EverCure Billing manages the full claim lifecycle for US practices, from eligibility verification and authorization tracking through claim scrubbing, submission, remittance posting, denial appeals, and aged accounts receivable recovery. Rejection and denial reports are worked on a daily cadence, denials are trended by reason code and payer, and the resulting fixes are pushed back into front-end and coding processes so the same denial category does not repeat.
For a review of your current denial reasons and aged claims,
contact EverCure Billing at info@evercurebilling.com or (929) 249-5929.
Frequently Asked Questions
About Medical Claims
Claim adjudication is the payer internal process of reviewing a submitted claim against member eligibility, benefit coverage, medical policy, authorization requirements, and the contracted fee schedule to determine payment, patient responsibility, and any denied amounts.
An explanation of benefits is the payment explanation sent to the patient, describing what the plan covered and what the patient owes. An electronic remittance advice is the 835 transaction sent to the provider, describing allowed amounts, payments, adjustments, and reason codes at claim and line level for posting.
Coordination of benefits is the process of determining which plan pays first when a patient has more than one insurance policy. The primary plan adjudicates first, and the remaining balance is then billed to the secondary plan with the primary remittance attached. Outdated COB information on file with the payer is a frequent and easily corrected denial cause.
Clean electronic claims are commonly adjudicated within roughly two to four weeks, though the exact timeline depends on the payer, the claim type, and applicable state prompt-pay laws. Claims requiring records, authorization review, coordination of benefits, or appeal take significantly longer, which is why days in accounts receivable is tracked as an average rather than a fixed expectation.
A superbill is an itemized encounter summary listing the provider, patient, diagnoses, procedures, and charges from a visit. It is not a claim. It serves either as the internal source document for charge entry, or as a document the patient submits to their insurer for out-of-network reimbursement.
A denied claim can be resubmitted as a corrected claim when the denial was caused by an error the provider can fix, such as a wrong modifier, incorrect member ID, or missing referral number. When the payer decision itself is being disputed, for example a medical necessity denial, a formal appeal with supporting documentation is required rather than resubmission, which would otherwise trigger a duplicate denial.
When a claim is unpaid because of a provider-side error such as a missed filing deadline or missing authorization, the balance is generally not billable to the patient and becomes a practice write-off. When the service is genuinely non-covered under the plan and the patient was properly notified in advance, the balance is patient responsibility. Documentation of that advance notice is what determines the outcome.
Need Help With Your Medical Claims?
EverCure Billing provides end-to-end medical claims management and revenue cycle support for US healthcare practices. Contact us today for a free assessment.