Switching billing companies: a transition timeline and checklist

How do you switch billing companies without a cash flow gap?

Pick one go-live date, keep every claim owned by exactly one company on any given day, and move the payment route only after the new route is confirmed in writing. Most cash gaps come from claims that sat in nobody's queue or from payments that still landed in an account the new team could not see.

A switch moves four things. This guide takes them in the order a billing manager has to touch them, with the official rule behind each one. It is general information, not legal advice. Have counsel review your agreement, because notice, fees and data return are contract terms.

What does a billing transition timeline look like?

No regulation sets how long a billing transition takes. The length is set by the slowest dependency, which is usually payer enrollment for payment changes, your notice period, and how old your open claims are. Work backward from the go-live date you can defend, not forward from the day you sign.

The sequence below is a planning order, not a rule. Treat the phases as gates: do not start a phase until the one before it has a named owner and a written result.

Which clocks keep running during the switch?

Deadlines do not pause for a vendor change. Put each of these on one calendar owned by someone on your side.

What if my contract has a notice period?

The notice period in your agreement controls when you can end it, and giving notice early or late can cost money either way. Read the termination clause, any automatic renewal date, and what the company keeps working after you leave.

Send notice the way the contract says to send it, and keep proof. Then ask for the exit package in writing before the last day: the data files below, the run-out terms, and the name of the person who answers questions after you leave. The billing company contract checklist lists these clauses line by line, so this guide does not repeat them.

One federal term helps you here. A business associate agreement must require the vendor, at termination and if feasible, to return or destroy the protected health information it still holds, and to keep no copies (45 CFR 164.504(e)(2)(ii)(J)). If returning it is not feasible, the agreement must extend its protections and limit further use. Ask for a written certificate once the return is done.

What should I request from my old billing company?

Ask for claim-level data, not summary reports. A summary tells you the total; the claim-level file lets the new company work each claim and prove nothing was lost.

Ask for the files in a format the new company can load, such as delimited text or the system's native export, and ask which fields are included. Request a test file early, because the first export is rarely complete.

What data should migrate from the EHR and practice management system?

Migrate what a claim needs to be built and what an appeal needs to be defended: patient demographics, insurance and subscriber details, charge and procedure history, diagnosis codes, authorization numbers, and the documentation attached to open claims. Everything else can stay in the source system and be exported on request.

Your EHR may stay the same while only the billing team changes. In that case the work is access and report setup, not migration, and the plan is a user list and a charge feed. The EHR pages list the systems we work with.

Keep your own copy of the records. Under 42 CFR 424.516(f), a provider or supplier that furnishes covered ordered, certified, referred or prescribed Part A or B services must maintain documentation for 7 years from the date of service and give access to CMS or a Medicare contractor on request. That duty stays with you when a vendor leaves, so confirm you can still read the data you gave away.

• Patient and guarantor demographics, with the last update date
• Primary and secondary coverage, group and subscriber IDs, and eligibility verification dates
• Charges, procedure and diagnosis codes, modifiers and rendering provider for every open claim
• Authorizations and referrals on file, with their dates and unit counts
• Fee schedules, the charge master and its code crosswalk
• Attached documents for open claims and appeals: notes, consents, records sent

What happens to open A/R when we switch?

Open accounts receivable can stay with the old company, move to the new company, or be split. The split is a written agreement, and the one thing it must answer is who works each claim and who gets paid for collecting it.

Whatever you choose, write the cutoff as a rule a spreadsheet can test. For example: every claim with a first submission date before go-live belongs to the old company, and every claim entered on or after go-live belongs to the new one. Then check twenty claims by hand against the file.

Medicare's one-year filing limit is the clock that punishes a dropped claim most plainly. Under 42 CFR 424.44(a)(1), the claim must be filed no later than the close of the period ending 1 calendar year after the date of service. Unbilled claims in a vendor's queue are the biggest source of write-offs in a switch, so ask for that list first.

Whoever works the old balances, ask for the order of work in writing, and keep the filing and appeal date of each claim in view. Our A/R recovery service covers this work.

How do I move ERA and EFT to a new billing company?

Keep the bank account in your name, change only who can see the remittances, and file each payer's enrollment before the first payment is expected on the new route. The billing company should never become the account holder.

For Medicare, the EFT authorization is Form CMS-588. Its instructions say the account must carry the name of the physician or practitioner, or the legal business name of the entity enrolled in Medicare, and that the signer certifies that person or entity has sole control of the account. A provider may have only one EFT account per enrollment. The form must be signed by the Authorized Representative or Delegated Official named on the CMS-855 enrollment application on file, and uploaded to PECOS or mailed to the MAC. One form is needed for each Medicare contractor you bill.

CMS also warns that all EFT requests go through a pre-certification period in which the bank verifies the account before any Medicare direct deposits are made. That period is the reason the payment change goes in early, not on go-live day.

What is the Medicare ERA and EDI paperwork?

An ERA is the electronic remittance advice, the 835 file that explains a payment. Medicare's manual says each provider that receives ERA through a billing agent or clearinghouse must sign an ERA enrollment form and submit it to the MAC before the MAC will send ERA. A separate EDI enrollment form covers claim transactions.

When you change billing agents or clearinghouses, the manual says providers are obligated to notify the MAC in writing in advance, including the date they will stop using the old one. Whether a new form is also required depends on the MAC's own process, so ask the MAC. The new company must also get its own EDI access number and password from the MAC. A provider is not allowed to share its own EDI number and password with a billing agent or clearinghouse.

The EDI agreements between you and the third party are kept by the provider and are not submitted to Medicare, according to the same manual section.

How do commercial payers handle EFT and ERA changes?

Each commercial payer runs its own enrollment, so the answer lives in that payer's provider manual or portal. Federal rules standardize what the enrollment collects. The rule at 45 CFR 162.1603 adopts the Phase III CORE EFT enrollment data rule, the ERA enrollment data rule, and a rule for matching an EFT payment to its 835 remittance, using the CCD+ and 835 pair. It does not set a form or a wait time.

Medicare may pay an agent who provides billing and collection services only if five conditions are met, including that the agent's compensation is not related in any way to the dollar amounts billed or collected, and that the agent acts under payment disposition instructions the provider can change or revoke at any time (42 CFR 424.73(b)(3)). Payment is made in the name of the provider. Ask counsel how your fee structure and your account setup fit those conditions.

Do I need a new clearinghouse?

Not always. If the new company sends claims through the clearinghouse you already use, you may only need to change user access and the submitter setup. If it uses its own, every payer needs to know the new route, and the payer ID list has to match.

A clearinghouse is the company that receives your claims, checks them and passes them to the payer. A change usually involves three things: a new submitter ID, enrollment with each payer for claims and ERA through that route, and a check of the payer ID for each plan, so check each payer's own published ID list for every transaction you send.

• Ask which payer IDs the new route uses for each of your top payers, and compare them with the old list.
• Keep the old clearinghouse account active until the last claim it sent has been paid or denied, and until the last ERA enrollment through it ends.
• Ask each payer which route receives the remittance for a claim already in process when the route changes.
• Send a small batch of real claims first and watch the acceptance reports before sending volume.

Who tells the payers about the change?

You do, because you are the enrolled party. The new company can prepare the forms and track the answers, but the signatures that matter come from your authorized officials.

CAQH's own quick reference says only the provider can authorize who has access to a profile. A billing change does not change who is authorized, but it is a good moment to confirm that every payer you contract with is listed, since credentialing and billing teams often share the same blind spot. Profiles must be re-attested every 120 days, or 180 days for providers in Illinois.

For the credentialing work behind a new location or a new group, see credentialing new locations. That guide covers enrollment steps; this one covers the billing route.

Which logins and portals should change hands?

Every shared password is a risk and a delay. Give the new company its own named logins, remove the old company's on the cutoff date, and keep the master accounts in your name.

Two-step login on every system is the standard to ask for. Take that up with each vendor, and write the list of who has access to what into the transition plan, with a date each login ends.

How do I avoid duplicate claim submission during the transition?

Give each claim one owner and keep a ledger that shows the owner and the date it changed. Duplicates come from two teams both working a claim that looks unpaid.

A payer that already has a claim will deny the second copy as an exact duplicate, which is the reason code CO-18. The duplicate also pulls attention away from claims that are really missing. A corrected claim is a different filing from a duplicate, and each payer's manual says how a correction must be marked.

• Freeze submission from the old route on the cutoff date, and move only claims the ledger shows as unsent.
• Mark claims in process with the payer's claim number, so the new team checks status first.
• Share one status list each morning during the overlap, with a named person on each side.
• Count claims by payer on both sides at the end of each day, and explain any difference.

What about open appeals and timely filing clocks?

Each open appeal and each unbilled claim has its own date. Put them in the handoff file with the date the clock started, the date it ends, and who owns the next step.

A Medicare redetermination request must be filed within 120 calendar days from the date a party receives the notice of the initial determination (42 CFR 405.942(a)). The date of receipt is presumed to be 5 calendar days after the notice date, and the request counts as filed on the date the contractor receives it. The five levels of appeal are covered on Medicare appeal levels.

Commercial payers set their own filing and appeal limits in their manuals or contracts, and a corrected claim is usually held to the same window as the original. The numbers for three large payers are on the timely filing limits page. Read your own agreement before you rely on any table.

Will cash flow dip during a switch?

It can, and the honest plan assumes a dip and shortens it. The dip comes from charges held while systems are set up, payment routes that take time to enroll, and early claim rejections caused by setup errors.

Track cash by week against the baseline you froze: total payments posted, deposits received, claims sent and claims rejected. A dip that is explained and shrinking is a plan working. A dip with no explanation by the third week is a reason to stop and look at the claim counts.

How do I vet the new company's onboarding plan?

Ask for a written plan with named owners, dates and the handoff terms, then check it against the sections of this guide. A plan that cannot say who signs the Medicare payment forms, or where payments will land, is not finished.

• Who owns each step, and what is the date and written result?
• Where will payments land, and whose name is on the account?
• Which claims does each company own on go-live day, and how is that tested?
• What access does each person get, and when does the old access end?
• Is a business associate agreement signed before any patient data moves?
• What does the first month of reporting show, and who reviews it with you?

For a deeper vendor comparison, see choosing a billing partner, and for the security questions to ask, see is it safe to outsource medical billing.

How does Nucleus Align handle a billing transition?

We align each EHR, clearinghouse and payer portal workflow with verified team experience, standard claim validation, reconciliation controls and performance monitoring. A transition plan names the owner of every claim, every payer enrollment and every login before go-live.

Once your claims are on our route, claims go out within 24 hours of charge entry and denials are worked within 48 hours, with automated eligibility checks and multiple claim scrubbing rules before submission. We sign a Business Associate Agreement with every client, give all staff HIPAA training and NDAs, use two-step login on every system and keep encrypted automatic backups.

Our clients see 15 to 20% revenue recovered from denials and old A/R, Our revenue cycle management service covers the full cycle. To talk through a switch, book a call.