Why Does Medicare Deny CO-22 for Patients Who Are Still Working Past 65?
The visit was clean. The coding was right, the note was complete, and you billed Medicare like you do for every other patient over 65.
How to Stop Working-Aged Claims From Denying CO-22
The goal is simple: every Medicare patient screened for a primary payer before the claim drops, so the working-aged ones bill in the right order the first time. Here is what does that, move by move.
1. Run the MSP Questionnaire at Intake, Every Medicare Patient
The denial starts at registration, so that is where you stop it. Medicare expects providers to gather coordination-of-benefits data using the Medicare Secondary Payer questionnaire, and it is the front-line tool for catching a working-aged patient before you bill. Ask every Medicare patient the questions that matter: are you or your spouse currently working, is the employer large, are you covered by a group health plan through that job. When the answer flags a working-aged situation, you have caught it before the claim exists rather than after Medicare bounces it.
2. Re-Screen Every Year, Because Employment Status Changes
A one-time screening at the first visit is not enough. A patient who retired last year and made Medicare primary may have gone back to work; a spouse's coverage may have started or ended. Medicare's own guidance treats MSP status as something to verify on an ongoing basis, so re-run the questionnaire at least annually for every Medicare patient on the panel. The working-aged situation you missed is usually the one where last year's answer quietly stopped being true, and nobody asked again.
3. Identify the Primary Payer Before the Claim Drops
Once the questionnaire flags a group health plan through current employment at a large employer, treat that plan as primary. Capture the plan name, member ID, and payer ID at intake, verify the coverage is active, and note the coordination-of-benefits order in the account before anyone bills. The whole point is to know the billing order at the desk, not to discover it on a CO-22 remittance three weeks later when the visit is already old.
4. Bill the Group Plan Primary, Then Medicare Secondary
With the order known, the claim goes to the employer plan first. When that plan pays or denies, you submit to Medicare secondary with the primary remittance attached so Medicare can coordinate benefits and pay its portion. Done in the right order, the claim never generates a CO-22 in the first place, and the working-aged patient stops being the account that reworks itself every visit. For claims that already denied, the same rework rebills to the primary and then to Medicare secondary with proof of the original filing to protect timely filing.
5. Hand MSP Screening and Secondary Billing to a Dedicated Team
Practices that stop reworking working-aged denials do it by handing MSP screening and coordination of benefits to a dedicated team: remote specialists who run the questionnaire, verify the primary payer, bill in the right order, and rework the CO-22s that already landed, live in 1 to 2 weeks. The front desk stops guessing at coverage between check-ins, a trained backup covers every gap, and the working-aged patient stops being the denial nobody owns. Below is what it sounds like when nobody owns it yet, in providers' own words.
Key Pain Points and Discussions by Providers
representative composite examples based on common workflow discussions
“We bill Medicare for a patient who is clearly over 65 and it comes back CO-22 telling us there is another primary payer. Half the time nobody at the desk knew the patient was still working, because we never actually ask. It is a clean visit we now have to unwind.” composite example: billing lead, primary care practice
“The MSP questionnaire is on our intake form, but it gets skipped when the waiting room is full. Then three weeks later I am the one reworking the denial, calling the patient to find out where they work and whether the spouse has a plan. That conversation should have happened at check-in.” composite example: practice administrator, primary care group
“What kills us is the patients who retired, went back to work, and never told us. Last year Medicare was primary, this year the employer plan is, and our system still had it the old way. The first sign we get is a CO-22, and by then the visit is aging.” composite example: office manager, family medicine practice
“We screen new patients once and never again. So the working-aged ones who change jobs or whose spouse picks up new coverage slip right through, and every one of those is a denial and a rebill in the wrong order.” composite example: billing lead, multi-provider practice
“Reworking a CO-22 is not just resubmitting. I have to bill the employer plan, wait for that remittance, then send Medicare secondary with the paperwork attached. One skipped question at the front desk turns into a month of me chasing the right billing order.” composite example: coder, primary care practice
Our Answer
Here is what we actually do. A dedicated remote specialist runs the Medicare Secondary Payer questionnaire for every Medicare patient at intake and again each year, so a working-aged patient with a group health plan through current employment is caught before the claim drops. They capture the primary payer, verify the coverage is active, and set the coordination-of-benefits order in the account, then bill the employer plan first and Medicare secondary with the primary remittance attached. For CO-22 denials that already landed, they rebill in the correct order with proof of the original filing to protect timely filing. Our teams include trained healthcare operations professionals with backgrounds that may include medicine, nursing, and pharmacy, working inside your practice management and clearinghouse tools, with approved AI tools assisting with first-pass and a human verifying every submission. This is our denial management support paired with an AI-first workflow, in one paragraph.
Why This Keeps Happening
If the visit was clean, why does Medicare keep denying it CO-22? Because the denial has nothing to do with the visit. Under the Medicare Secondary Payer rules, a patient age 65 or older who is covered by a group health plan through their own or a spouse's current employment at an employer with 20 or more employees has that group plan as their primary payer, and Medicare pays secondary. CMS is explicit that providers are expected to gather this coordination-of-benefits information, and the MSP questionnaire is the tool built for it. When the question never gets asked, the practice bills Medicare in good faith, and Medicare returns the claim because it was never first in line.
The gap is almost always at the front desk, not the billing office. Intake is the one moment you can ask a patient directly whether they or their spouse are still working, at what size employer, and under what plan, and it is the moment most likely to get skipped when the schedule is full. So the working-aged status the practice needed to know never enters the account, and the claim routes to Medicare by default. Catching it at registration is exactly the kind of front-office accuracy an insurance eligibility verification workflow is built to protect, because the denial is decided before a single code is entered.
And the cost is not just one reworked claim. A CO-22 rework is not a resubmission; it is billing the employer plan primary, waiting on that remittance, and then filing Medicare secondary with the primary explanation of benefits attached, all while the visit ages toward a timely filing deadline. Multiply that across a Medicare-heavy panel where working-past-65 is increasingly common, and the quiet miss at intake becomes a standing pile of secondary rebills, delayed cash, and accounts that sometimes age out entirely before anyone untangles the billing order.
Most groups have already tried the obvious fixes before they talk to anyone. Each one fails the same way: the work lands back on the practice. The pattern, in one table:
| What you tried | What actually happened | Who ended up doing the work |
|---|---|---|
| Put the MSP questionnaire on the intake form | It gets skipped when the waiting room is full, so the working-aged status never reaches the claim | Whoever was at the check-in desk that day |
| Screened new patients once at their first visit | Patients who returned to work or whose spouse gained coverage slipped through and denied CO-22 anyway | A one-time form nobody revisited |
| Reworked each CO-22 as it landed | Turned a clean visit into a month of billing the employer plan, waiting, then filing Medicare secondary | The billing office, one denial at a time |
| Gave MSP screening to a dedicated remote specialist | Every Medicare patient screened at intake and yearly, primary payer set before the claim drops, denials reworked in order | Someone whose whole job it is |
The Solution
So what does "someone whose whole job it is" look like on a working-aged Medicare patient? The specialist runs the MSP questionnaire at intake for every Medicare patient, not just new ones, and asks the questions that actually decide the billing order: current employment, employer size, spouse coverage, group health plan. When a patient flags as working-aged, they capture the employer plan as primary, verify it is active, and set the coordination-of-benefits order in the account before anyone bills. That front-office catch is exactly what dedicated insurance eligibility verification is built to do, before a clean visit ever becomes a CO-22.
Then comes the part the front desk rarely has time for: billing in the right order and reworking the ones that already denied. The specialist bills the group plan primary, waits on that remittance, and submits Medicare secondary with the primary explanation of benefits attached so Medicare can coordinate benefits correctly. For CO-22s already on the aging report, they rebill in the proper sequence with proof of the original filing so timely filing is protected. The accounts that used to sit and age get worked the same way every time, on a schedule.
Behind all of it, Approved AI tools may assist with the first pass and a trained human reviewer verifies. The workflow flags which Medicare patients are due for re-screening, drafts the coordination-of-benefits order, and queues the secondary claim; a person confirms the primary payer is right and owns the rework. Every security control that protects the patient and coverage data moving through that process is documented and auditable, and the whole approach is described on our HIPAA and security page, because moving eligibility and claim data through an outsourced workflow is only safe when the controls are real.
Who Actually Does This Work
Fair question: why would an outsourced team screen your Medicare patients better than your own front desk? Because coordination of benefits is their entire day, not the thing they squeeze between a full waiting room and a ringing phone. The people running your MSP screening and secondary billing include trained healthcare operations professionals with backgrounds that may include medicine, nursing, and pharmacy, all trained in US registration, eligibility, and coordination-of-benefits workflows. They know what the MSP questionnaire is checking for, how the working-aged rule works, and how to bill Medicare secondary correctly, so a working-past-65 patient is caught at intake instead of discovered on a remittance.
We are not a call center. We are a clinical operations partner, a healthcare BPO built on dedicated virtual staff: 500+ team members, 24/7 coverage, and the AI-assisted plus human-verified workflow you just read about behind every one of them. A typical practice is live in 1 to 2 weeks, at approximately 68% below equivalent in-house staffing costs. Trained backup coverage is included in the managed-service model.
And the security piece your compliance officer will ask about: Staffingly maintains active ISO/IEC 27001:2022 certification and operates under HIPAA-compliant controls and signed BAAs. SOC 2 Type II reporting and security controls apply according to the relevant entity, client environment, facility, device, and workflow. Venn Blue Border and related workstation restrictions are used where applicable. Staffingly maintains $5M in professional liability (E&O) and cyber insurance as part of its enterprise risk-management program; the full detail lives in our HIPAA and security posture.
Put the routine and the people together, and a specific list of things simply stops happening.
Ready to Stop Reworking Working-Aged Denials?
Evaluating the best insurance eligibility verification services? See how a dedicated remote team compares, then browse every pain point we solve.
How We Build a More Durable Process
A person alone is not the fix, and neither is a bot alone. The fix is a documented coordination-of-benefits workflow: which Medicare patients get screened, when they get re-screened, exactly which MSP questions decide the billing order, and how a working-aged claim gets billed primary then secondary. Before we take a single account for a new practice, we chart your Medicare panel and your CO-22 history so we can see where working-aged patients are actually slipping through, and we build the screening cadence against that, not against a generic checklist.
From there the workflow becomes a living playbook rather than a form nobody revisits. It records which questions to ask, how to read a working-aged answer, how to set the coordination-of-benefits order in your system, and the exact steps to bill the employer plan primary and Medicare secondary with the right attachments. It is written down, kept current, and owned by the team. When your specialist is out, a trained backup runs the same questionnaire and the same billing order, so a working-aged patient does not have to slip because one person was away that week.
That is the difference between reworking this month's CO-22s and fixing the process for good, and it is what a dedicated revenue cycle management partner actually buys you. A coordinator leaving used to mean the MSP screening quietly stopped and the working-aged denials came back. Under this model the screening keeps running, the playbook stays, the backup steps in, and a CO-22 stops being the denial that reworks itself every visit.
The Whole Thing in Four Sentences
Medicare denies CO-22 for patients working past 65 because the Medicare Secondary Payer rules make a group health plan primary when the patient or spouse is still working at an employer with 20 or more employees, and intake never ran the MSP questionnaire to catch it, so the claim routed to Medicare first. Skipping the questionnaire, screening only once, or reworking each denial as it lands all fail the same way. The fix is to run the MSP questionnaire at intake and every year, identify the primary payer before the claim drops, bill the group plan primary, and submit Medicare secondary with the primary remittance attached. A primary care group can use this workflow without exposing patient information or naming client organizations.
If you want to check us out before talking to anyone: our security posture is independently auditable, we are an MGMA 2026 Corporate Member, and 800+ providers run back office work with us.
Ready to stop reworking working-aged denials? Start with a Two-Week Free Trial: your real Medicare panel and CO-22 queue, dedicated specialists running the MSP screening and billing in the right order, and if it does not earn the handoff, you walk away. From here down is the sales part, and it is short: here is exactly what it costs.
One Flat Weekly Rate. 45 Hours of Coverage.
No hourly meters, no setup fees, no security deposits, no long-term contracts. Two-Week Free Trial. Your dedicated team member covers your desk 45 hours every week, and a trained backup steps in at no charge whenever they are out.
One dedicated remote specialist owning your MSP screening and CO-22 denial rework end to end, single-location primary care practice
5+ remote specialists covering coordination of benefits and secondary billing across a multi-provider group or several sites
10+ remote specialists, multi-location primary care group, MSO, or PE-backed platform running MSP screening and secondary claims across many front desks
45 hours of coverage at one flat weekly rate.
For a simple annual comparison, 40 hrs x 52 weeks = 2,080 hours. A Staffingly plan: 45 hrs x 52 weeks = 2,340 hours a year, that is 260 additional hours included in your flat rate. $399/week x 52 = $20,748 a year / 2,340 hours = $8.87 per hour.
Catch Working-Aged Patients Before the CO-22 This Month
You have seen the whole method. The trial lets you test it on your own Medicare panel, with a tracker your team can watch every day.
Start My Two-Week Free TrialWant Us to Stop Reworking Working-Aged Denials?
Tell us your situation and we will map your Medicare panel, your MSP screening, and the CO-22 rework behind it. A team member will follow up with next steps.
Frequently Asked Questions
Where the Claims on This Page Come From
Sources & References
- Centers for Medicare and Medicaid Services, Medicare Secondary Payer Overview. Official CMS guidance on coordination of benefits, the working-aged provision, and when a group health plan is primary to Medicare. cms.gov
- CMS Medicare Secondary Payer (MSP) Manual, Chapter 3. Detailed MSP provisions and the provider responsibility to gather coordination-of-benefits data, including the model MSP questionnaire. cms.gov
- CMS Medicare Secondary Payer Fact Sheet (MLN006903). Provider-facing summary of MSP rules, the working-aged category, and correct primary-then-secondary billing order. cms.gov