3,533 Referring NPIs Medicare Lists Both Ways

The Opt Out Affidavits file carries a column most billing shops have never opened. It is called Eligible to Order and Refer, it holds a Y or an N, and in the July 2026 edition 26,517 of the 55,948 live opt-out records carry the N.

That is 47% of every practitioner who has signed out of Medicare and stayed out.

The N lands where you would not guess, and it tracks the affidavit rather than the credential (chart below). Psychiatry runs 4,061 Y against 804 N. Family Practice runs 2,622 against 177.

Sixty-four separate specialties contain both answers, so the only way to know is to look up the NPI.

The Column That Decides the Claim

Nothing about this is cosmetic. Under 42 CFR 424.507, a claim for ordered imaging, clinical lab, or DMEPOS pays only if the ordering practitioner is "enrolled in Medicare in an approved status" or has "validly opted-out of the Medicare program." Home health and hospice get the same two-part test in paragraph (b).

Paragraph (c) is the part that shows up on your remittance:

"a Medicare contractor denies a claim from a provider or a supplier for covered items and services described in paragraph (a) or (b) of this section if the claim does not meet the requirements"

So an opt-out is a perfectly good ordering provider, right up until the file says otherwise. And the file is where the eligibility gets set: the practitioner qualifies by putting an SSN, a date of birth, and an NPI on the affidavit, and per Noridian, if "any required element is missing, the provider will not be approved to order, certify, and/or prescribe." There is also a box on the form. Check No and you are set up as an N forever, because opt-out affidavits auto-renew every two years unless the practitioner cancels at least 30 days before expiry.

An administrative checkbox on a form somebody signed in 2024 decides whether your claim pays in 2026.