Template · Published Sep 3, 2026 · Updated Sep 2026

Locum Coverage Ops: The Credentialing and Access Checklist

Bringing in a locum to cover an absence only works if the substitute can actually practice, bill, and get into the building. Miss the credentialing, the billing set-up, or the access, and you have a provider who is present but cannot function. This checklist makes locum coverage real.

Locum coverage has four workstreams that must all be ready before the substitute starts: credentialing and privileging, payer and billing set-up, systems and building access, and documentation of the arrangement. For Medicare, billing runs under a fee-for-time compensation arrangement with modifier Q6, a 60-day continuous limit, and per-diem pay; Medicaid, Medicare Advantage, and commercial payers set their own rules. Start early, because credentialing gates everything.

A physician is out for the summer, so you bring in a locum to cover. The scheduling problem feels solved. But a locum is not coverage the moment they walk in; they are coverage only when they can practice where you need them, bill for what they do, and actually use your systems and your building. Get the operational set-up wrong and you have paid for a provider who is physically present but cannot fully function, which is not coverage at all. Here is the checklist that makes it real.

Present is not the same as ready

The mistake practices make with locum coverage is treating the scheduling, finding a substitute for the dates, as the whole job, when it is only the start. A locum who has not been credentialed and privileged where they are covering may not be authorized to practice there. A locum whose billing is not set up correctly generates services that cannot be billed, or that get billed wrong and denied. A locum who has no login to your EHR, no access to your systems, and no badge for the building cannot actually do the work even though they are standing in the office. Each of these turns expensive coverage into a provider who is present but blocked, and each is invisible until the locum arrives and hits the wall. The fix is to treat locum onboarding as a real operational project with several parallel workstreams, all of which must be complete before day one, exactly the mindset that credentialing any provider requires, laid out in the credentialing process guide. Present is not ready. Ready means credentialed, billable, and able to work, and getting there takes deliberate set-up started well ahead of the coverage dates.

The four workstreams

Locum onboarding breaks into four workstreams. Run them in parallel, and finish all four before the locum starts.

The documentation workstream is easy to overlook and matters for compliance: keep a record of the reason for the regular provider's absence, the dates covered, the identity of both providers, and confirmation that the substitute is paid on a per-diem or fee-for-time basis. The credentialing workstream is the one with the longest lead time, so it drives your start date, the same timeline reality covered in the credentialing timelines guide, and if the locum needs hospital privileges near you, that follows the pattern in the privileges guide.

The Medicare billing rules

The billing workstream deserves precision, because the Medicare rules are specific and getting them wrong means denials or overpayment exposure. Medicare formally calls the arrangement a fee-for-time compensation arrangement (the traditional term is locum tenens), governed by the CMS Claims Processing Manual, Publication 100-04, Chapter 1, Section 30.2.11. Under it, the regular physician bills for the substitute's covered services under the regular physician's own NPI, with modifier Q6 appended to each service to indicate it was furnished under the arrangement. The regular physician must keep a record of each service along with the substitute's NPI, available to Medicare on request. The substitute must be paid on a per-diem or fee-for-time basis, not as an employee. And there is a 60-day continuous limit: a substitute generally cannot cover the regular physician's Medicare patients for a continuous period longer than 60 days, with a narrow exception for physicians called to active military duty; once the regular physician returns, a new 60-day period can begin if another substitute is later needed. Note also that this fee-for-time arrangement is distinct from reciprocal billing, a different Medicare arrangement with its own rules, so confirm which one applies. Track the continuous period carefully, because the 60-day limit is exactly the kind of date that slips.

Other payers differ

A critical caveat that trips up practices: the rules above are specific to Medicare fee-for-service. Medicaid, Medicare Advantage, and commercial payers each set their own requirements for substitute-provider coverage, and those can differ significantly from Medicare's, some may not recognize the arrangement the same way, may require the locum to be separately credentialed and enrolled, or may apply different billing rules entirely. So the payer workstream is not one task but one per major payer: confirm, before coverage begins, how each of your significant payers handles a substitute provider, rather than assuming Medicare's fee-for-time rules apply across the board. This is exactly where a locum arrangement quietly generates unbillable or denied services, when a practice applies Medicare's approach to a commercial payer that wanted something different. The operational safeguard is simple: as part of onboarding, run down your payer list and verify each one's locum policy, and set up billing per payer accordingly. It is more work than a single rule would be, but it is the difference between a locum whose services are all billable and one whose coverage leaks revenue through misbilled claims. This checklist is an operational guide, not billing or legal advice; confirm the specifics for your payers and situation.

Running it early

The thread through all four workstreams is time, so the operational lesson is to start early. Credentialing and privileging take weeks to months, payer set-up takes coordination, and access provisioning takes lead time with your vendors, which means a locum arranged a few weeks before the absence will not be ready when the absence begins. For predictable coverage needs, seasonal absences like summer, planned leave, start the locum onboarding well ahead, treating the coverage date as a deadline you back-plan from, the same renewal-math discipline that protects every other deadline in the practice. Build a reusable locum onboarding checklist so each engagement runs the same four workstreams without rediscovering them each time, and assign an owner, usually the practice manager, to drive it to completion before day one. Locum coverage, done as a real operational project, genuinely solves the problem it is meant to: the practice keeps seeing patients through an absence, and does so with a provider who can fully function and bill from the first day. Done as an afterthought, it produces an expensive provider who cannot work at full capacity. The difference is entirely in the set-up, and the set-up is entirely doable, if you start it in time. Pair it with your broader coverage planning in the vacation coverage guide and the handoff work in the handoff pack.

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