ChecklistReimbursement
The 48 hours that decide an infusion's margin
In drug-heavy ID work, prior authorization is not administrative overhead — it is the control that stands between a course of therapy and a written-off vial.
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ID · Reimbursement
Two Halves: Money Lost in the Note, and Money Lost on the Vial
Revenue cycle in infectious disease has two distinct halves: cognitive billing, where money is lost in the note, and drug-heavy billing, where a single claim can carry weeks of acquisition cost. They need different controls.
Drug reimbursement
Buy-and-bill, and what it puts on your balance sheet
A practice that acquires its own drugs is running a small distribution business with working capital, inventory and payment risk.
Under buy-and-bill you purchase the drug, hold it, administer it and bill afterwards — capturing whatever spread exists between acquisition and payment, and carrying the exposure that comes with it. Under white-bagging a specialty pharmacy supplies the drug for a named patient: no acquisition cost, no spread, less control. Payer preference between these models directly determines whether your infusion business has drug revenue at all, which makes it a contracting issue.
Medicare Part B separately payable drugs are broadly paid on an average sales price methodology, published by CMS on a quarterly cycle. Payment moves independently of what you paid for inventory, and your acquisition cost depends on your own purchasing arrangements — so the spread is practice-specific, drug-specific and time-specific.
Worth holding on to
- We publish no drug figures
- Acquisition costs, ASP-based payments and margins vary by drug, arrangement, quarter and payer. Use your own.
- Reconcile inventory monthly
- A discrepancy is either uncosted wastage or uncaptured charges.
- Load your contracts
- Underpayment on drug claims is invisible without them.
Sources & further reading
Prior authorization
The control that stands between inventory and a write-off
Verify coverage, obtain authorisation, acquire drug, administer, bill. Every reordering moves risk onto your balance sheet.
Where clinical urgency genuinely requires starting ahead of approval, make it a named exception with a defined approver and a recorded exposure — not a silent absorption.
The most commonly missed step is reauthorisation. Initial approvals cover a defined duration; antimicrobial courses extend for clinical reasons. If nothing triggers a filing before the approved period expires, therapy continues into a coverage gap and the denial arrives after weeks of drug has been administered. Build the expiry date into the system that schedules the infusions.
Worth holding on to
- Criteria sheets, versioned
- One page per drug per payer: required, criteria, channel, turnaround.
- Clock starts at referral
- Not at first submission.
- Embed criteria in templates
- Documentation then satisfies requirements as a by-product of good notes.
Coding & documentation
Where a cognitive specialty leaks revenue
When E/M is the product, documentation is the product specification.
Under-levelling is a real and under-discussed leak. Compliance training focuses on over-coding risk, and the practical result is systematic downward drift — revenue never billed, appearing in no report at all. Audit in both directions: sample your encounters, compare documented complexity to selected level, and report the distribution.
Where level selection is time-based, the time must be documented in a form that supports it. ID work is unusually rich in qualifying activities — record review, inter-clinician discussion, coordination, independent interpretation — and practices that fail to capture the time forfeit the level.
Infusion and injection services follow a defined hierarchy with rules on initial, subsequent and sequential services and documented start and stop times. High volume means a systematic error is a systematic loss.
Worth holding on to
- Audit quarterly, both directions
- Under-levelling is a training finding, not a compliance failure.
- Capture the time
- Extensive coordination described without recorded time does not support time-based selection.
- Verify current rules
- Check CPT guidance, payer policy and your MAC's LCDs before changing workflow.
Denials & leakage
Rank by dollars, and hunt the underpayments
In drug-heavy practice, one denied claim can outweigh a month of office visits.
A count-ranked denial report inverts entirely when ranked by dollars. Let the dollar ranking drive the work. And treat hard denials as what they are in a buy-and-bill model: realised losses on goods already consumed, not deferred revenue.
Root-cause categories should include the ones specific to this work — authorisation absent or expired, site-of-care mismatch, drug unit and wastage reporting, medical necessity on the specific agent, and administration coding — alongside the standard front-end causes.
The silent failure is contractual underpayment. A drug claim paid below the contracted amount produces no rejection and no alert. Given individual claim values, loading contracted rates is the highest-leverage single control an infusion practice can implement.
Worth holding on to
- Hard-denial dollars as a standing metric
- It is the direct cost of upstream process failure.
- Quarterly payment-variance review
- Across your highest-value drug claims, against contracted rates.
- One category per month
- Largest by dollars, owned by the step that produces it, with a date.
Sources & further reading
Related resources
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Buy-and-bill, explained without the jargon
Why a practice that dispenses expensive drugs is running a small pharmaceutical distribution business, and what that means for cash, risk and authorisation.
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When evaluation and management is the product, documentation is the product specification. The recurring places ID practices under-capture.
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