Free, cited, nothing gated
Opening a practice in the United States
The enrollment and credentialing rules that decide when you can actually get paid, each one cited to the regulation or to CMS rather than to another billing company’s blog. Three things almost everybody publishes about this are out of date; those are marked.
Opening a practice is a revenue-timing problem before it is anything else. Nearly every expensive mistake in the first year is the same shape: work was done before a date that a form set, and no amount of good billing afterwards recovers it.
These guides cover the dates. They are written for somebody with the question open in front of them right now, so each one leads with the answer.
Can you bill Medicare before your enrollment is approved?
Up to 30 days before your effective date, and only if circumstances genuinely precluded enrolling in advance. That is the maximum, and everything before it is gone for good.
Read the rule
CY2026 · $750The Medicare application fee is $750 — and most physicians do not owe it
The CY2026 fee is $750.00, and it applies to institutional providers only. A physician filing a CMS-855I does not pay it, and neither does a physician or NPP group practice.
Read the rule
CMS-855CMS-855I or CMS-855B — and why the 855R no longer exists
The CMS-855R was discontinued and merged into the CMS-855I. MACs have returned newly submitted applications on the old form since 1 November 2023.
Read the rule
NPPESNPI Type 1 vs Type 2 — which does your practice need?
Type 1 is you, the individual, including if you are a sole proprietor. Type 2 is an organization. An incorporated physician often needs both.
Read the rule
42 CFR 424.515Missed your Medicare revalidation? What deactivation actually costs
CMS can place a hold on your reimbursement or deactivate your billing privileges — and says it will not reimburse for services furnished during the deactivated period.
Read the rule
CAQH · 120 daysCAQH re-attestation is every 120 days — and the reminder schedule is not what vendors say
Every 120 days, or 180 days for Illinois providers. Miss it and your profile goes to Expired status the day after it was due.
Read the rule
Check your own revalidation date, free
CMS publishes every provider’s revalidation due date as an open dataset. We indexed all 2,440,081 NPIs in it. Type yours and read it — no email, nothing stored.
Questions
What is the single most expensive mistake when opening a practice?
Seeing patients before filing the Medicare enrollment application. Under 42 CFR 424.520(d) your effective date is the later of your filing date and the date you first furnished services, and 42 CFR 424.521 allows retrospective billing only 30 days before that effective date. Open in March, file in May, and March is never billable.
How much of this can I do myself?
All of it. None of these pages is gated and none of them ends in a form you have to fill in to see the answer. They exist because the accurate version is hard to find, not because we want to trade it for your email address.
Why should I trust these numbers over a billing company blog?
Because every one of them links to the regulation or the CMS document it came from, and you can check it in one click. Three widely repeated claims are wrong and we say so with the source: the CMS-855R no longer exists, physicians and group practices are not subject to the application fee, and CAQH does not send a 30-day re-attestation reminder.
Every source used in this cluster
- 42 CFR 424.520 — effective date of billing privileges
- 42 CFR 424.521 — retrospective billing
- 42 CFR 424.515 — revalidation of enrollment information
- 42 CFR 424.502 — definition of institutional provider
- Federal Register, 3 December 2025 — CY2026 application fee
- CMS Application Fee Requirement Matrix (PDF)
- CMS — Revalidations
- CMS NPI Fact Sheet (PDF)
- CMS NPI booklet, ICN 902603 (PDF)
- CMS consolidated CMS-855I bulletin (PDF)
- CMS — Medicare enrollment applications
- CAQH Provider User Guide v43 (PDF)
- CAQH — for providers
- CMS PECOS 2.0 FAQs (PDF)
- CMS Revalidation Due Date List (open dataset)
These are research summaries, not legal or enrollment advice. Enrollment rules are set by CMS and each payer, which is why every claim above links to the source instead of asking you to take our word for it.
If this is work somebody on your team is doing at four in the afternoon, it can be a seat.
Next step
Credentialing is somebody's whole job, not a Friday afternoon
A credentialing seat works enrollments, revalidations and CAQH attestation so a date never arrives unannounced.
Or write to ops@softhomeglobal.com