A physician who starts on January 4 and has not been enrolled with the practice's payers will see patients for eight to twelve weeks whose claims cannot be billed under that physician. Many of those claims will be denied with CO-B7, provider not eligible on the date of service, and some will pass timely filing before enrollment catches up. We see this every winter, and it is almost always because the credentialing work started in November.
The fourth quarter concentrates credentialing risk. Many state medical licenses renew on a fixed cycle that lands at year end. Malpractice policies frequently renew January 1. Payers run recredentialing on three-year cycles that often started with a January contract. New hires start with the new year. Each item on its own is manageable. Together, on a two-person office staff who also run the front desk, they are how things get missed.
This is the checklist our credentialing team works from October through December. It is ordered by lead time, longest first, because the items with the longest lead times are the ones you cannot recover from in December.
Key takeaways
- New-provider enrollment for a January start should already be submitted. If it isn't, submit this week and tell the owner which payers will not be effective on day one.
- CAQH profiles must be re-attested every 120 days, and every uploaded document must be current. The malpractice certificate is the one that breaks files in January.
- Build one expiring-document list across all providers and renew anything that expires before March 31, 2027 in October and November.
- Check every provider's and the group's Medicare revalidation due date now. A missed revalidation deactivates billing with no retroactive payment for the gap.
- Ask your top payers for their roster of your providers in writing. Roster errors turn into CO-B7 denials in the first quarter.
1. New providers starting in January: start now
Payer enrollment timelines depend on the payer, but in our experience Medicare enrollment through PECOS commonly takes 45 to 90 days, Medicaid varies by state and often runs longer, and commercial plans commonly quote 90 to 120 days and sometimes take longer. A provider starting January 4 should have had applications submitted in September. If that did not happen, submit everything this week and set expectations with the practice owner about which payers will and will not be effective on day one.
Where the contract allows, ask about retroactive effective dates; some commercial plans will backdate to the application received date, many will not. Medicare's rules allow a physician or practitioner to bill for services furnished up to 30 days before the date the enrollment application was received, provided all enrollment requirements were met on those dates, which is one reason to submit early even if documents are still being gathered. The received date, not the approval date, is the one that matters, so get the application in and correct it later if the contractor asks.
Work backward from the start date. For a January 4, 2027 start, the count looks like this: commercial applications needed to be in by early September; Medicare by mid-October at the latest; Medicaid by whatever the state's published processing time says, plus a month. Every practice we know that hits January starts cleanly has a rule that the credentialing file opens the day the offer letter is signed, not the day the provider arrives.
2. CAQH re-attestation: every 120 days, without exception
CAQH asks providers to re-attest their profile every 120 days. Payers pull from that profile during credentialing and recredentialing, and an expired attestation stalls the file without anyone telling you. Before January, we check every provider's profile for four things:
- Attestation date within the last 120 days, and a calendar reminder for the next one.
- Every uploaded document current: state license, DEA registration, malpractice certificate of insurance with the policy period visible, board certification, and a W-9 that matches the group's legal name and tax ID.
- Practice locations, hospital affiliations and the supervising or collaborating relationships for advanced practice providers matching what is on the payer contracts.
- Authorizations granted to each payer that needs to see the profile.
The document that most often breaks a file in January is the malpractice certificate, because the new policy period starts January 1 and nobody uploads the new certificate until a payer asks in March. Ask the carrier or broker in November for the renewal certificate to be issued the day the policy renews, and upload it the same week.
The second most common break is the W-9. A practice that changed its legal name, added a location or moved its tax ID during the year will have payers matching a stale W-9 against a new one, and the mismatch stops payment rather than credentialing. Check that the W-9 on CAQH, the W-9 on file with each payer and the IRS letter all say the same thing.
3. Expiring documents: build the date list
Pull a single spreadsheet with every provider and every expiring credential: license (and any second-state license), DEA, state controlled-substance registration where applicable, board certification, CLIA certificate for the practice, malpractice policy period, and hospital privileges reappointment. Sort by expiration date. Anything expiring before March 31, 2027 gets renewed in October and November, because renewal boards are slow in December and payers will not accept an expired document even for a week.
Add a column for who renews it. Licenses and DEA registrations are the provider's to renew, and providers forget; the credentialing coordinator's job is to remind them in writing at 90, 60 and 30 days and to collect the new certificate the day it is issued. The CLIA certificate and the group's own documents belong to the practice manager. A list with no owner column is a list that will be read once.
4. Medicare revalidation: check the due dates
Medicare requires revalidation every five years for most physician and group enrollments, and CMS publishes each enrollment's due date in its revalidation lookup tool, generally several months in advance. The contractor also mails or emails a notice, but notices go to the address on the enrollment record, which is often wrong for a practice that has moved or changed managers. Check every provider and the group itself, and check the reassignments too: a physician's individual enrollment and the group's enrollment revalidate on separate dates.
A revalidation that is missed leads to deactivation, and a deactivated enrollment stops payment for every claim until it is reactivated, without retroactive payment for the gap. This is the single most expensive credentialing mistake a practice can make, and it is entirely preventable with a five-minute lookup each quarter.
5. Payer recredentialing and roster checks
Payers usually recredential every 36 months. Ask each of your top payers, in writing, for the recredentialing date of every provider on the contract and the group's roster as the payer sees it. Rosters drift: a provider who left in 2024 still listed, a new location missing, a nurse practitioner billed under a supervising physician who is no longer on the contract. Roster errors show up as CO-B7 denials and as patients told the practice is out of network. Fixing them before January avoids a cluster of denials in the first quarter.
When the roster comes back, compare it line by line to the practice's own provider list and to the rendering providers on last month's claims. Every mismatch is either a provider the payer needs to add, a provider the practice should have terminated from the contract, or a location the payer does not have. Send the corrections in one letter per payer and keep the payer's acknowledgment with the contract.
Fourth-quarter timeline
| When | Task |
|---|---|
| First two weeks of October | Submit all applications for January starts; pull the expiring-document list with owners; check Medicare revalidation dates for every provider and the group |
| Rest of October | Renew anything expiring before March 31; re-attest CAQH for every provider; request payer rosters and recredentialing dates in writing |
| November | Follow up on every application every two weeks and log the contact; correct roster errors; confirm new malpractice policy details with the carrier; check W-9s match everywhere |
| December | Upload new malpractice certificates as soon as issued; confirm effective dates for January starts in writing; brief the billing team on which providers can be billed to which payers from day one |
Questions we hear
Can a new provider see patients before enrollment is complete?
Clinically, yes. Financially, it depends on the payer and the contract. Some commercial contracts allow billing under a supervising physician in specific circumstances, and Medicare has its own rules for incident-to services that are narrower than most practices assume. Talk to the practice's counsel or compliance advisor before deciding to bill under another provider; the fix for a slow enrollment is not a compliance risk.
Who should own CAQH?
One person in the practice, with the provider's login credentials stored securely and a 120-day calendar. Providers who manage their own profiles almost always let attestations lapse. If nobody in the office has the time, this is the piece of the work that most practices hand to a credentialing partner first, and it is the piece with the most consistent payoff.
We missed the window for a January start. What now?
Submit everything immediately, ask each payer about retroactive effective dates, and build a schedule for the new provider that leans toward payers who are already effective. Then put the next new hire on a 120-day lead time from the day the offer letter is signed.
What to do this week
- List every provider starting between now and March and confirm each application is submitted, with the received date recorded.
- Look up the Medicare revalidation due date for every provider and for the group, and put each one on the calendar 90 days ahead.
- Build the expiring-document spreadsheet with an owner column, and send the first reminder for anything expiring before March 31.
- Open every CAQH profile, re-attest, and check the malpractice certificate, the W-9 and the payer authorizations.
- Email your five largest payers asking for the current roster and recredentialing dates in writing.
