Medicare Advantage, a Working-Aged Group Health Plan, and an Unauthorized Chondroplasty
Mrs. Chen, 72, is enrolled in a Medicare Advantage HMO and is also covered by her current employer's group health plan (58 employees), where she still works 30 hours a week. She is scheduled for knee arthroscopy. On Monday the biller verifies eligibility through the MA plan's portal, obtains prior authorization #A-4471 for CPT 29881 valid for 60 days, and notes the auth does not mention any other code. The surgeon performs 29881 and also a chondroplasty (29877) in a separate compartment, documented in the operative report. The biller submits the claim to the MA plan first. Both lines deny with CARC 22 ("this care may be covered by another payer per coordination of benefits"), and a later notice denies 29877 as not authorized. The surgeon asks whether the patient can simply be billed for the balance since the plan refused to pay.
1. Which payer is primary here and what is the correct billing sequence? Cite the rule that drives your answer.
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The employer group health plan is primary; the MA plan is secondary.
- The Medicare Secondary Payer working-aged rule: when a beneficiary is covered by an employer group health plan through current employment (her own or a spouse's) and the employer has 20 or more employees, the group health plan pays first and Medicare pays second. The MA plan stands in Medicare's shoes and must follow the same order.
- Because the biller sent the claim to the MA plan first, the CARC 22 denial is correct. The claim was in the wrong order.
- Sequence to follow: (1) bill the group health plan with the operative report and both CPT codes; (2) when the GHP EOB arrives, submit to the MA plan as secondary, attaching the primary EOB and the primary allowed/paid amounts; (3) confirm both plans hold the same COB record so the crossover does not loop.
- Watch the edge case: a retiree plan not based on current employment would reverse the order. Verify employment status and the plan's basis of coverage, and document the verification date.
- Prior authorization requirements do not disappear because a plan is secondary - check the MA plan's secondary-payer auth rules before assuming #A-4471 is enough.
2. May the practice bill Mrs. Chen for 29877 because the MA plan denied it as unauthorized?
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Generally no - the provider bears the risk of a missing authorization.
- Under Medicare Advantage rules, when a network provider furnishes a service without required prior authorization, the MA organization may deny payment to the provider, and the provider cannot shift that denial to the enrollee when the service would otherwise have been covered. The financial consequence of a process failure stays with the practice.
- An ABN is not the tool here. The ABN is a traditional Medicare document and is not used to create MA beneficiary liability. The MA plan issues its own denial notices to the enrollee; the practice cannot manufacture patient liability with an ABN.
- Realistic remedies, in order: (1) request retroactive authorization with the operative report, citing the separate compartment and the medical necessity of the chondroplasty; (2) file a plan-level reconsideration with the op note showing the chondroplasty was distinct from the meniscectomy; (3) request a peer-to-peer if the plan allows it.
- Separately, check whether 29877 is bundled into 29881 under NCCI. If it is, the claim needs the appropriate distinct-service modifier and documentation of the separate compartment - otherwise the code is not separately payable regardless of authorization, and the write-off is correct.
3. What should happen to the account while the authorization and COB issues are being resolved?
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Hold the balance; do not bill the patient and do not send to collections.
- The account is in an active payer dispute, not a patient-responsibility status. Billing the patient now would create a refund obligation if the plan later pays, and would expose the practice to a grievance.
- Practical steps: set a status flag ("COB/auth pending - do not bill"), note the auth number, the denial dates, and the 60-day auth window; calendar the appeal deadline from the date of each denial, not from the date of service.
- Refund/credit check: if the group health plan pays more than the MA plan's secondary allowable, apply the lesser-of logic and expect a secondary payment that may be zero. Do not collect the difference from the patient; it is a contractual adjustment.
- Process fix worth documenting in the review: the original auth was obtained for a single code. The scheduler should have flagged the possibility of additional codes from the op note and requested a broader auth or verified the plan's policy for concurrent procedures.