A denied claim rarely traces back to one mistake. More often it points to a weak spot between scheduling, documentation, coding, and follow-up, and that spot keeps producing denials until someone finds it. This guide covers the medical billing denial management process from first remittance to prevention, using CPT Code 93015, the global cardiovascular stress test code, as the running example. Stress testing teaches well because one service can be billed as a single code or as three, depending on who did the work and where.
What is denial management in medical billing?
Denial management in healthcare billing is the routine of finding denied claims, learning why they were denied, correcting or appealing them, and using the findings to prevent repeats. A denial means the payer processed the claim and refused all or part of it. The remittance explains why through a group code, a claim adjustment reason code (CARC), and usually a remark code. A rejection is different. The claim failed an upfront edit, such as a missing field, and never reached adjudication, so it is repaired and resent rather than appealed.
Types of denials in medical billing
Most denials fall into three working categories, and sorting them correctly decides who fixes them.
- Administrative denials come from process gaps: lapsed eligibility, missing precertification or authorization (CARC 197), duplicate claims, and missed filing limits.
- Clinical denials question whether a service was medically necessary (CARC 50).
- Coding denials involve the code, modifier, or diagnosis: a bundled service (CARC 97), a modifier mismatch (CARC 4), or a diagnosis that does not fit the procedure (CARC 11).
Authorization denials in medical billing straddle categories. A missing authorization is administrative; a payer declining a requested one is making a clinical judgment.
The medical billing denial management process, step by step
A working denial management workflow runs as a loop: remittance received → denial categorized → root cause found → claim corrected or appealed → unanswered claims escalated → results tracked → fixes sent back to the front end.
1. Capture and categorize
Post the electronic remittance and read all three layers: group code, CARC, and remark code. Assign each denial a category and a work queue, then rank the queue by appeal deadline before dollar value, since a missed filing window cannot be repaired.
2. Find the root cause
Pull the claim, eligibility check, authorization record, order, clinical note, and payer policy, then decide whether the denial was valid. A wrong code or an incomplete record is the practice’s error and calls for a correction. A payer that bundles something the CPT descriptor allows you to report has made the error, which calls for an appeal.
3. Correct, resubmit, or appeal
Data and coding errors go back as corrected claims, while disputes over coverage or necessity go through appeals. Under Original Medicare, a redetermination is due within 120 days of receiving the initial determination notice, and a Qualified Independent Contractor reconsideration within 180 days of receiving the redetermination. Noridian also cautions that a reopening (365-day window) is not an appeal, and choosing one by mistake can cost the appeal deadline. Commercial payers set limits by contract, so log each payer’s deadline in the work queue.
A strong appeal letter identifies the claim, states the denial reason, cites the policy language or CPT descriptor that supports payment, and attaches the records. Appeals are underused: KFF’s analysis of 2023 CMS data found that 11.7% of denied prior authorization requests in Medicare Advantage were appealed, and 81.7% of those appeals were partly or fully overturned. Those figures cover one program’s authorization decisions, not every claim denial.
4. Escalate claims that go unanswered
Some claims never produce a remittance. The escalation process for unresponsive claims in medical billing begins with the clearinghouse acceptance report, which confirms the payer received the claim. Check status on the payer portal, then call provider services and record the representative’s name and a call reference number. If inquiries stall, move to a provider relations contact or supervisor, cite the contract’s payment-timeline terms and any state prompt-pay law, and request a written reply. Every contact belongs in the account notes.
5. Track and prevent
Log each denial by payer, CARC, CPT code, and root cause, and review clusters monthly. The same payer, reason code, or procedure recurring shows where to intervene. Denied balances also age quietly in accounts receivable (AR), so AR denial management should report them by age bucket, apart from ordinary open claims. Return each finding to its source: the front desk for eligibility and authorization, coders for modifiers and bundling, clinicians for documentation gaps.
CPT Code 93015 as a denial management case study
What CPT Code 93015 describes
The CPT 93015 description covers a complete cardiovascular stress test performed with treadmill or bicycle exercise at maximal or submaximal effort, continuous ECG monitoring, and/or pharmacological stress, with supervision, interpretation, and report. CPT belongs to the AMA, and Noridian’s revision history notes that the short or long descriptors for 93015 through 93018 changed effective January 1, 2026. Check the current codebook rather than an older reference page.
93015 compared with 93016, 93017, and 93018
| Code | Reports | Typically billed by |
|---|---|---|
| 93015 | Complete test: supervision, tracing, interpretation and report | One physician or practice that performs every part |
| 93016 | Supervision only | The supervising physician |
| 93017 | Tracing only, no interpretation or report | The party supplying equipment and staff (often a hospital) |
| 93018 | Interpretation and report only | The interpreting physician |
The three component codes describe the same work as 93015, so they are not reported alongside it for one test. MedLearn Media’s coding Q&A says the global code suits a physician who owns the equipment and employs the staff in an office or clinic, while a hospital-performed test is split: the hospital reports 93017, and the physician reports 93016 and, when also interpreting, 93018. Stress test billing guidelines differ among commercial payers, so confirm against the payer’s policy. Stress echocardiography code 93351 already includes ECG monitoring and supervision, so pairing it with this family invites a bundling denial. Check NCCI edits for the date of service before combining stress codes.
Documentation and medical necessity
Under Noridian’s billing and coding article A57183 (version effective October 1, 2026, covering Jurisdictions E and F), claim documentation should show a clinical diagnosis, the specific reason for the study, the reason for any pharmacological stress, the referral order, the interpretation and report, the necessity of the testing frequency, and that supervision requirements were met. The article treats routine follow-up testing after a heart attack, bypass, or angioplasty as not reasonable and necessary when the patient has no symptoms and the test falls outside the reassessment period, and it says the same of annual testing without individualized indications. Chest pain, unspecified (R07.9) appears on its list of supporting diagnoses. Medical necessity rules belong to each MAC and payer, so a diagnosis accepted in one jurisdiction can fail in another.
Reimbursement considerations
No single payment figure applies to CPT Code 93015. Medicare prices physician services through its fee schedule, which combines relative value units, geographic adjustments, and a conversion factor, with values updated annually. Facility and non-facility settings are priced differently, and component billing divides payment among the reporting providers. Commercial payers pay by contract. Any dollar amount quoted without a payer, locality, setting, and date of service should not be trusted.
Three hypothetical 93015 denial scenarios
These are illustrative examples, not real cases, and payers differ.
Coding denial
A cardiology office bills 93015 for a test run in a hospital outpatient department, where the hospital also bills 93017. The payer denies the line as included in another service (CARC 97). If the physician supervised and interpreted, the office corrects the claim to 93016 and 93018, and appeals only if records show it owned the equipment and staff.
Clinical denial
A Medicare patient with a stent placed years ago and no new symptoms has an annual stress test, and the claim returns with CARC 50. Under a policy like Noridian’s, an appeal is realistic only if the note documents new symptoms or a changed clinical picture. Without a signed ABN, the practice generally cannot bill the patient for the denied amount.
Administrative denial
A commercial plan that requires authorization for outpatient stress tests returns CARC 197. Staff discover the approval existed but its number never reached the claim, so a corrected claim, not an appeal, resolves it. Whether a plan requires such authorization varies.
Pre-submission review for stress test claims
- Name who supervised, who recorded the tracing, and who interpreted, then choose 93015 or the component codes to match.
- Confirm the place of service and whether a facility is billing 93017.
- Compare the diagnosis with the payer’s coverage policy and the documented reason for the test.
- Verify the order, signed report, and supervision statement are in the record.
- Check NCCI edits for same-day services, and add modifier 25 to an E/M visit only when it is significant and separately identifiable.
- Confirm eligibility, authorization, and the timely filing limit.
Keeping CPT Code 93015 claims out of the denial queue
CPT Code 93015 reports a complete cardiovascular stress test billed by one provider, while 93016, 93017, and 93018 divide the same work among the supervisor, the technical provider, and the interpreter. Medical necessity depends on documentation: the diagnosis, reason for the test, order, report, and supervision record. Reimbursement varies by payer, locality, setting, and date of service. A sound medical billing denial management process ties these together by categorizing every denial, finding its cause, acting before the deadline, and returning the lesson to whoever builds the claim.
Before the next stress test claim goes out, write down who supervised, who ran the tracing, and who signed the report. If the answers do not map cleanly to 93015 or to a set of component codes, the claim is not ready.