There are ten weeks left in the year. Every denied claim from the spring and summer that is still sitting in accounts receivable is moving toward a timely filing limit, and every denial cause that is still active will produce the same denials in January under new fee schedules and new codes. A fourth-quarter denial review deals with both at once. It is a week of work for a billing lead and a coder, and it is the highest-return week of the year.
What follows is how we run it. It is not a clean-up of the AR list; that happens every week. It is a structured look at every denial received since January 1, sorted by cause, with a hard decision on each bucket and a deadline list that someone owns. The output fits on two pages: a one-page bucket summary and a one-page list of claims that expire before December 31.
Key takeaways
- Pull three reports for the same window (denials by CARC and RARC, open AR with original submission dates, and denial write-offs) and work in a spreadsheet, not in the practice management system.
- Group denials into seven causes the practice can act on, then count claims and sum dollars by payer; the biggest bucket by count is almost never the biggest by money.
- Run the timely filing audit in the same week and work the December expiration list before anything else.
- Every bucket gets one of three decisions: rework, write off with a specific reason, or fix the cause before January.
Pull three reports for the same window
Use January 1 to September 30, 2024 as the window, so the fourth quarter's own denials are not mixed in before they have had a chance to be worked. Pull:
- Denials by claim adjustment reason code (CARC) and remark code (RARC), with payer, date of service, billed amount and current status. Most practice management systems call this the denial detail or ERA denial report.
- Open AR by payer and age bucket, with the original submission date on each claim, not just the date of service.
- Adjustments posted with a denial or non-covered write-off code, so you can see what was written off without an appeal, and by whom.
Export all three to a spreadsheet. The reports in the system are fine for working claims one at a time; they are bad at showing patterns, and they cannot join the denial to the original submission date, which is the join that makes the timely filing audit possible.
Sort into buckets by cause, not by code
CARC codes are numerous and inconsistent across payers; the same eligibility problem arrives as CO-27 from one plan and CO-31 from another. Group them into causes the practice can act on:
| Bucket | Typical codes | Root cause lives in | Recoverable? |
|---|---|---|---|
| Eligibility and coverage | CO-27, CO-26, CO-31, PR-31 | Front desk, eligibility check | Often, by billing the correct payer |
| Authorization and referral | CO-197, CO-15 | Scheduling, authorization desk | Sometimes, with retro auth or appeal |
| Coding and bundling | CO-4, CO-97, CO-236, CO-11 | Coding, charge entry | Usually, with a corrected claim |
| Medical necessity | CO-50, CO-167 | Documentation, diagnosis linkage | Sometimes, with records |
| Duplicate and timely filing | CO-18, CO-29 | Billing process | Duplicates yes; timely filing rarely |
| Missing information | CO-16 with RARC | Claim setup, enrollment data | Usually, with a corrected claim |
| Credentialing and enrollment | CO-B7, CO-185 | Provider enrollment | Depends on effective date |
For each bucket, count the claims and sum the billed amount, then split by payer. The output fits on one page: seven buckets, top three payers each, dollars. That page is the review. Everything else in the week is about acting on it.
Define the terms once for the team. A CARC is the payer's reason for adjusting the payment; the CO prefix means the provider is contractually responsible and cannot bill the patient, and PR means patient responsibility. A RARC is the supplementary remark that explains the CARC, and CO-16 without its RARC is meaningless, so make sure the export carries both.
Run the timely filing audit in the same week
While the AR export is open, add two columns for each claim: the payer's timely filing limit from the contract, and the date it expires counted from the date of service (or from the date of the last payer response, for corrected claims and appeals, depending on the contract). Then filter for anything expiring before December 31, 2024.
| Payer type | Typical initial claim window | Corrected claim or appeal window | Where to confirm |
|---|---|---|---|
| Medicare Part B | 12 months from date of service | Redetermination within 120 days of the remittance | MAC website |
| Commercial, contracted | 90, 120 or 180 days from date of service | Often 60 to 180 days from the denial; varies by contract | The contract's claims section, then the provider manual |
| Medicare Advantage | Usually the contract window; some plans mirror Medicare | Plan appeal windows, commonly 60 days | Plan provider manual |
| Medicaid and Medicaid managed care | Varies by state, commonly 90 to 365 days | Varies by state and plan | State agency and MCO manuals |
The list that comes out is your December deadline list. Sort it by expiration date and dollar amount and work it first, before anything else in this review. A denied claim with a fixable cause and two weeks of filing window is worth more than any process improvement, because it is money that disappears on a specific date.
Look also for claims that were never submitted: encounters with charges and no claim history. Those are past timely filing for every payer if they are more than a year old, and there is usually no remedy. Count them anyway; the count tells you whether the encounter-to-claim reconciliation is working, and a nonzero number is a finding for the January process fix.
Make a decision on every bucket
Each bucket gets one of three decisions, written on the one-page summary next to the bucket:
- Rework. Corrected claims or appeals for everything still inside the filing window. Assign a name and a completion date before December 15, which leaves time for payer processing before the year closes.
- Write off with a reason. Anything past the filing window with no proof of timely submission. Post it with a specific adjustment code (timely filing, not "other" or "small balance"), so next year's review can see what was lost and why.
- Fix the cause. For the three largest buckets by dollar, identify the process step that produced them and change it before January. Name the owner and the date the change goes live.
A worked example
Take a five-provider multispecialty group running this review in late October. Denials for the nine months total 1,860 claims and $412,000 billed. Eligibility denials are 38% of the count but 22% of the dollars. Authorization denials are 9% of the count and 31% of the dollars, concentrated in one payer and two imaging codes. Coding denials are mostly modifier 25 and modifier 59 edits from a single commercial payer, and two providers generate most of them. The timely filing audit finds 71 claims worth $28,000 expiring before December 31, of which 54 are fixable eligibility denials that were never rebilled to the correct plan.
The decisions follow from the page. The 54 claims are reworked in two weeks, rebilled to the secondary or the correct plan. The 17 that lack documentation are written off with a timely filing code. Three changes go in for January: a two-day pre-visit eligibility check with a scripted secondary insurance question, an authorization hard stop for the two imaging codes at scheduling, and a modifier 25 documentation checklist for the two providers generating most of the coding denials. The group cannot know in October what those changes will do to next year's numbers, and neither can we. What it can know is that the three causes accounting for most of its lost dollars now have an owner and a date.
Mistakes that waste the week
Working the list top to bottom. Sort by expiration date and dollars first. A $40 copay dispute does not go before a $3,200 procedure expiring in November.
Appealing everything. An eligibility denial is not appealed; it is rebilled to the right payer. An authorization denial for a service already performed is appealed only if the contract allows retroactive review. Know which is which before you write letters.
Counting denials without dollars. The biggest bucket by count is almost never the biggest by money, as the example shows.
Skipping the write-off decision. Unrecoverable claims left in AR make every future report wrong and every future review harder, and they hide the real days-in-AR figure from the owners.
Reviewing without the front desk. The eligibility bucket is fixed at check-in, not in billing. If the people who check patients in are not in the room for the findings meeting, the fix does not happen.
Questions we hear
Should we include the fourth quarter's denials in the review?
Not in the analysis. October denials are still being worked in the normal weekly cycle and would distort the buckets. Do include them in the timely filing filter, because a September date of service with a 90-day commercial window expires in December.
Can we prove timely submission for a claim the payer says it never received?
Sometimes. A clearinghouse acceptance report showing the payer accepted the claim on a specific date is usually enough to reopen a timely filing denial. A claim that left the practice management system but was rejected at the clearinghouse and never resubmitted has no such proof. Pull the acceptance reports for the deadline list before you decide what to write off.
How is this different from the denial follow-up we do every week?
Weekly follow-up works claims. This review works causes and deadlines. The weekly work continues through the review; the review adds the one-page summary, the expiration list and the three fixes, and it happens once a year with the year-end in view.
What to do this month
- Pull the three reports for January 1 to September 30 this week and build the one-page bucket summary with claims, dollars and top three payers per bucket.
- Add the timely filing columns to the AR export, filter for expirations before December 31, and hand the list to whoever works AR, sorted by expiration date and dollars.
- Pull clearinghouse acceptance reports for every claim on the deadline list before deciding any write-offs.
- Write the rework, write-off or fix decision next to each bucket, with a name and a date.
- Schedule a one-hour meeting with providers and the front desk in early November to present the top three causes and the three fixes.
- If the team does not have the hours, the Revelrex denial management service runs this review for new practices in the first month, and practices that suspect the problem is upstream of denials can start with an RCM audit.
