An Ontario Medical Association survey of more than 2,500 physicians found that 90 percent had claims rejected in 2024. The question worth asking about your own practice is not whether this is happening to you. It is how much of it you have written off without ever counting.
OHIP claim rejections are only the visible layer. Underneath sits the revenue you earned and never collected, and most practices have no idea what their number is because nobody has ever calculated it.
What does billing leakage actually mean?
Billing leakage is work you performed, documented and were entitled to be paid for that never reached your bank account. It is not fraud, it is not aggressive coding, and it is not a grey area. A claim was rejected and never resubmitted, a code was never entered, or a deadline expired without anyone noticing. Most OHIP claim rejections are recoverable, and recovery only happens when somebody is looking.
The scale of the surrounding problem is documented. The OMA reports that more than 1.16 million claims a year are flagged for manual review, most appeals resolving in about 30 days, while roughly 58,000 claims take months or years to yield payment, which works out to about 1,000 cases a week sitting in limbo. Those figures also hide the cases where physicians never submit at all, because the administrative overhead costs more time than the claim is worth.
Where does the money actually leak?
Four places, and they behave differently. First, rejections that die on the vine. A claim comes back for an eligibility error, an invalid code, a version code mismatch or a service date problem. Someone sees the rejection, or does not, and it either gets corrected and resubmitted or written off by default. The write-off is rarely a decision. It is what happens when nobody owns the queue.
Second, stale-dated claims. Every provincial plan has a submission window, and in Ontario it is three months, after which claims are treated as over-age and payment is refused except in exceptional circumstances. This is the most painful category, because the money was fully earned and the only thing between you and it was calendar time.
Third, services rendered but never billed. The visit happened, the note is in the chart, and no claim was ever generated. This clusters in the gaps: after-hours work, procedures bundled into a visit and forgotten, services performed by a locum whose billing was never reconciled, virtual care with documentation requirements nobody flagged. Fourth, missed premiums, modifiers and bonus codes. The claim went in, it got paid, and it got paid less than it should have because an applicable premium was never applied. This is the most invisible leak of all, because nothing looks wrong. There is no rejection and no error message, only a smaller number than you were entitled to.
Why does this stay invisible?
Because every one of those four is invisible in the single report most physicians actually read, which is the deposit. Money arrives, the amount is plausible, the month closes. Leakage never appears as a loss. It appears as revenue that is slightly lower than it should have been, permanently, which is indistinguishable from a slow month unless you are running a reconciliation of submitted claims against paid claims line by line.
The structural problem compounds it. The OMA's position in its 2026 campaign is that the claims system has not kept pace with modern medicine, with the manual review backlog delaying payment for legitimate care across the province, particularly in surgical specialties where a high proportion of billings get flagged even when the procedure followed the standard of care. The OMA estimates that resolving these issues would free up enough physician time for at least 58,000 additional patient visits a year. That is the system-level cost, and it sits alongside the broader access pressures the same system is under. Your practice-level cost is a subset of it, and it is yours to find.
How do you calculate your own number?
Do not take anyone's benchmark, including the ones in this article, as your number. Run three calculations against your own data. First, your rejection recovery rate. Pull your rejections for a single quarter, count how many were corrected and resubmitted and how many were not. The percentage never reworked, multiplied by your average claim value, multiplied by four, is your annual rejection leakage. If nobody at your clinic can produce the rejection count, that is itself the finding.
Second, your stale-date exposure. Look for claims that hit the submission deadline unresolved in the past year. Every one is unrecoverable, and the count tells you whether your workflow has a follow-through problem or simply a volume problem. Third, your reconciliation gap. Take one month, pull the encounters recorded in your EMR, and match them against claims submitted. The delta is work you performed and never billed. Most practices doing this for the first time find something, and the something is usually a pattern rather than a one-off. If those three numbers take more than an afternoon to produce, you have found a fourth problem, which is that your billing process has no reporting layer.
Which fixes come first?
Give the rejection queue an owner. Not a process, a person. Rejections leak because they are everybody's job at the margins and nobody's job by name. One named person, a weekly cadence and a resubmission log turn the largest and most recoverable category into a managed workflow. It costs nothing and returns the most.
Validate eligibility at the front desk rather than at submission. A large share of rejections trace to health card and eligibility problems, and every one is fixable in ten seconds while the patient is standing in front of your receptionist. Catching it at the desk costs seconds. Catching it after submission costs a rework cycle and sometimes the whole claim. Then put a stale-date tripwire in place, so any claim approaching the deadline unresolved surfaces automatically rather than being discovered in a retrospective audit. Whether that lives in your billing software, your EMR or a spreadsheet someone maintains, the requirement is the same: nothing expires silently.
Audit your codes annually rather than never, because fee schedules change, premium eligibility changes and virtual care documentation requirements have shifted repeatedly. A yearly review of the codes your practice actually uses against the current schedule catches the underbilling nobody notices because nothing is visibly broken. Then decide deliberately about outsourcing. Third-party billing services typically charge a percentage of collections, and whether that maths works depends entirely on your current leakage rate, which is the number you now know how to calculate. If your recovery rate is already strong, outsourcing is an expense. If half your rejections are dying unworked, it may pay for itself several times over. One caution on all of this: the goal is capturing what you legitimately earned, never maximizing what you can arguably claim. Provincial plans audit, and coding decisions need to be defensible against your documentation.
Then track it monthly the way you track billings. Once leakage is a number on a dashboard with someone's name beside it, it behaves like every other number on a dashboard, and it goes down. Empty appointment slots and unbilled work are the same problem seen from two ends, and practices feeling both at once are usually also feeling the staffing pressures reshaping the wider system and the provincial scramble over family medicine capacity.
Frequently Asked Questions
What is billing leakage in a medical practice?
Revenue a practice earned and never collected. It arises from OHIP claim rejections that are never reworked, claims that pass their submission deadline, services documented but never billed, and applicable premiums or modifiers that were never applied. None of it involves inappropriate coding. All of it is legitimately earned work that failed to reach payment.
How long do you have to submit an OHIP claim?
Ontario's submission window is three months from the date of service. After roughly 90 days, claims are treated as over-age, and payment is generally refused except in defined exceptional circumstances. Unresolved rejections that pass that threshold become permanently unrecoverable, which makes deadline tracking the highest-value control in a billing workflow.
How do you calculate your practice's rejection recovery rate?
Pull one quarter of rejections, count how many were corrected and resubmitted, and count how many were never reworked. The proportion never reworked, multiplied by your average claim value and then by four, gives an annual estimate. If your practice cannot produce the rejection count at all, that gap is the first finding.
Is outsourcing medical billing worth it?
It depends on your current leakage rate. Third-party services typically charge a percentage of collections, so the calculation turns on how much revenue is currently dying in an unworked queue. Where recovery is already strong, outsourcing adds cost. Where a large share of rejections go unworked, it can pay for itself repeatedly.
Filling empty appointment slots is the other half of the same revenue problem. You can list your clinic and manage online booking through Medimap's platform for practices.
This article is general business information for health practice owners and administrators. It is not legal, accounting or billing advice. Fee schedules, submission deadlines and audit requirements vary by province and change over time, and you should confirm current requirements with your provincial plan or a qualified billing professional.
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