> ## Documentation Index > Fetch the complete documentation index at: https://mso.getlemma.com/llms.txt > Use this file to discover all available pages before exploring further. # Enroll and contract with commercial payers > Group contracting versus individual credentialing, letters of interest, closed panels, single-case agreements, reading a fee schedule, and negotiating effective dates. Commercial payer enrollment has two distinct halves: **contracting** puts your professional entity in the network at agreed rates, and **credentialing** verifies each clinician and links them to that contract. Both must complete before you get paid, and neither substitutes for the other. ## Prerequisites * The PC formed, with EIN, CP 575, and W-9 * Type 2 NPI with correct taxonomy * Each clinician's Type 1 NPI and an attested CAQH profile * Malpractice coverage meeting payer minimums * The PC's bank account for EFT ## Steps Find out which payers actually cover your patients. In most markets one or two plans dominate, and the local Blue is frequently the largest. See [The US payer landscape](/concepts/payments/the-payer-landscape). Most payers have an online form. You'll provide the PC's legal name, EIN, Type 2 NPI, taxonomy, service address, specialty, and clinician roster. "The panel is closed for your specialty in your area" is a real answer with no immediate appeal. Ask this **before** investing months. If closed, ask: * What would change the answer? (New location? Underserved area? Extended hours? A subspecialty?) * Is there a waitlist, and what is its timeframe? * Are **single-case agreements** available for individual patients in the meantime? **Never sign a contract without seeing the rates for your top codes.** Some payers resist providing them pre-signature; push. A contract at 70% of Medicare may be worse for you than being out of network, and you cannot evaluate that without the numbers. Ask for the allowed amounts for your 20 highest-volume codes, and confirm whether the schedule references **current-year** Medicare or a frozen prior year. See [Underpayments, fee schedules, and payer contracts](/concepts/payments/underpayments-and-contracts). | Clause | Why | | ------------------------------- | -------------------------------------------------------------------------------------------- | | Timely filing limit | Some commercial contracts run 90 days | | Appeal deadline | Separate from timely filing, often shorter | | Takeback / recoupment window | How far back can they recover, and can they offset automatically? | | Unilateral amendment | Can they change rates with notice and no consent? | | **Network access / assignment** | This is how rental networks and silent PPOs reach your rates | | All-products clause | Participating in one product may bind you to Medicaid MCO or MA products at much lower rates | | Termination | Notice period, with and without cause, by product or across the board | Signed by the PC's authorized officer. The MSO provides contracting **support**; the PC signs. See [What an MSO can and can't do](/concepts/model/what-msos-can-and-cant-do). Most payers pull from CAQH. Confirm the payer is **authorized** in each clinician's profile and that attestation is current. Expect 90–180 days. Committees often meet monthly, so missing a cycle costs a month. Ask explicitly for an effective date backdated to the application date or the practice start date. Some payers grant it routinely; many do not. **You will never get one you didn't ask for**, and asking after the fact is much weaker. Separate from contracting and credentialing. See [Set up EDI, ERA, and EFT](/guides/enrollment/set-up-edi-era-eft). Applications rarely get denied — they go quiet. Call, note who you spoke to, when, and what they said. That log is what gets a retro-effective date approved later. ## Single-case agreements A one-off agreement to cover a specific patient's care at a negotiated rate, used when you're out of network but the patient needs you. Useful when: the panel is closed; a patient has a continuity-of-care need; you provide a service unavailable in-network; or an existing patient's plan changed. Get it **in writing before delivering the care**, with the rate, the authorized services, and the timeframe specified. A verbal agreement to "work something out" is not a single-case agreement. ## Delegated credentialing Once you have scale, typically dozens of clinicians, some payers will delegate credentialing to you under a delegation agreement, subject to their audit. It shortens onboarding dramatically. Worth asking about once you're large enough. It requires an auditable, documented credentialing process, which is another reason to build one properly from the start. ## Verify it worked * [ ] Fee schedule reviewed before signing * [ ] Timely filing limit and appeal deadline recorded in the tracking grid * [ ] Network access and all-products clauses understood * [ ] Contract executed by the **PC's** officer; effective date recorded * [ ] Each clinician credentialed and linked; provider effective dates recorded * [ ] Retro-effective dates requested in writing * [ ] EDI, ERA, and EFT complete, with EFT to the PC's account * [ ] Follow-up log maintained ## Common failure modes | Failure | Consequence | | -------------------------------------------------------------- | ---------------------------------------------------- | | Signing without seeing rates | A contract that loses money on every visit | | Missing the timely filing limit in the contract | Write-offs from day one | | Confusing contract effective date with provider effective date | Billing for services before the clinician was linked | | CAQH attestation lapses mid-review | Application stalls silently | | Payer not authorized in CAQH | Same | | MSO signs the contract | CPOM problem; possibly an unenforceable contract | | No follow-up log | No basis for a retro-effective date request | | Not asking about retro dates | Months of unbillable services | ## Related topics - [Step 8: Enroll with your first payer](/start/zero-to-paid/enroll-with-your-first-payer.md) - [Credential each new provider you hire](/guides/enrollment/credential-new-providers.md) - [Handle credentialing delays and gaps](/guides/enrollment/handle-credentialing-delays.md) - [Set up EDI, ERA, and EFT with each payer](/guides/enrollment/set-up-edi-era-eft.md) - [Underpayments, fee schedules, and payer contracts](/concepts/payments/underpayments-and-contracts.md) - [The US payer landscape](/concepts/payments/the-payer-landscape.md) - [How to use the payer reference](/reference/payers/overview.md) - [Timely filing limits by payer](/reference/payers/timely-filing-limits.md)