How to Verify a DEA Number

By DEA Lookup.com, Inc. · Updated October 1, 2026

Short answer: Verifying a DEA number takes two steps. First, check that the number is formatted correctly: two letters followed by seven digits, with a check digit that satisfies the DEA checksum formula. Second, and more important, confirm the registration is active by checking it against primary source DEA registration data. That check also shows the expiration date, authorized drug schedules, and registered address. A number can pass the checksum and still be expired, retired, or invalid for the drug being dispensed.

What is a DEA number?

A DEA number is the registration number the U.S. Drug Enforcement Administration issues to people and organizations authorized to handle controlled substances under the Controlled Substances Act. Prescribers, pharmacies, hospitals, manufacturers, and distributors all hold DEA registrations. Pharmacies, distributors, and credentialing teams verify DEA numbers before dispensing, shipping, or credentialing, because a bad registration creates regulatory and financial risk.

Step 1: Check the DEA number format

A DEA number has two letters followed by seven digits, for example AB1234563.

Position	What it means
1st letter	Registrant type. C: are practitioners and similar registrants. M: are mid-level practitioners such as nurse practitioners and physician assistants. Other letters cover manufacturers, distributors, hospitals, pharmacies and other business activities.
2nd letter	Usually the first letter of the registrant's last name, or of the business name.
Digits 1–6	The registrant's unique number.
Digit 7	A check digit calculated from the first six digits.

The DEA number checksum formula

Add the 1st, 3rd, and 5th digits.
Add the 2nd, 4th, and 6th digits, then multiply that sum by 2.
Add the two results together.
The last digit of that total must equal the 7th digit.

Worked example for AB1234563 (a made-up number):

1st + 3rd + 5th digits: 1 + 3 + 5 = 9
2nd + 4th + 6th digits: (2 + 4 + 6) × 2 = 24
9 + 24 = 33. The last digit is 3, which matches the 7th digit, so the format is valid.

Step 2: Confirm the registration is active (the step that matters)

The checksum catches typos and made-up numbers. It does not tell you whether the registration is real, current, or appropriate for the transaction. For that you need to check the number against the DEA's registrant data, known as primary source verification (PSV). Confirm:

Status: active, not retired, revoked, or surrendered.
Expiration date: most practitioner registrations renew every three years.
Authorized schedules: the registration covers the drug schedule involved (for example, Schedule II).
Name and registered address: they match the prescriber, and the state matches where they practice.
Business activity: the registrant type fits the transaction.

Ways to verify a DEA registration

Since November 17, 2020, the National Technical Information Service (NTIS) no longer distributes the Controlled Substances Act registrant database. Access now runs through DEA, and your options depend on who you are:

Method	Best for	Trade-offs
DEA's online registrant validation (DEA Diversion Control Division)	Occasional checking by DEA number	Requires control access to your DEA registration to log in; one lookup at a time by DEA number only; no audit trail across your organization.
Primary source verification software or API (such as DEA Lookup.com)	Pharmacies, distributors, health systems, and credentialing teams that verify regularly or in bulk	A subscription, in exchange for fast searching, daily updates, batch validation - also rapid deployment and automation for application development.

Be cautious with free "DEA lookup" websites that don't disclose where their data comes from or how often it is updated. A stale copy of the data can show an expired registration as active.

Don't stop at the DEA number

A DEA registration alone doesn't make a prescriber eligible. Complete verification usually includes:

State license: active, unrestricted, and in the state of practice, verified with the state board.
State controlled substance registration: required in many states in addition to DEA.
NPI: confirms identity and ties the provider to claims and records.
Exclusion lists: OIG and SAM checks for providers barred from federal programs.

How DEA Lookup.com helps

For over 15 years, DEA Lookup.com has built primary source verification tools for pharmacies, distributors, and credentialing teams:

DEA License Lookup: desktop software that searches primary source DEA data by name, address, city, ZIP, or DEA number. It includes unlimited searches, daily updates, an encrypted data container with an audit trail, and downloadable proof-of-registration PDFs.
DEA List Validator: validates up to 1,000 DEA numbers at once.
DEA API Data Engine: builds DEA verification into order processing and credentialing systems.
State Medical License API: real-time primary source state license verification in all 50 states.
DEA to NPI Data Engine: cross-references DEA registrations to NPI numbers.

Frequently asked questions

Does a valid DEA number checksum prove the registration is active?

No. The checksum only confirms that the number is formatted correctly. A correctly formatted number can belong to a registration that is expired, retired, revoked, or restricted to certain drug schedules. Only a check against primary source DEA registration data confirms active status.

What do the letters in a DEA number mean?

The first letter identifies the registrant type: C for practitioners and similar registrants, and M for mid-level practitioners. Other letters cover manufacturers, distributors, hospitals, pharmacies and other business activities. The second letter is usually the first letter of the registrant's last name or business name.

How often do DEA registrations need to be renewed?

Most practitioner registrations are renewed every three years. Some registrant types renew annually. Because registrations expire and change, verification should be repeated, not done once.

Where does DEA registration data come from now that NTIS no longer distributes it?

Since November 17, 2020, NTIS no longer distributes the Controlled Substances Act registrant database. DEA registrants with control access can validate other registrants through DEA's registration validation tool, and certain other entities can apply for access. Organizations with access then need a system to search, update, and secure that data.

Is a DEA registration enough to prescribe controlled substances?

No. A practitioner also needs an active state license, and in many states a state controlled substance registration, in the state where they practice. Complete prescriber verification checks the DEA registration, the state license, and often the NPI together.

Verify DEA registrations with primary source data. Subscribe today or email sales@dealookup.com to schedule a demo.

DEA Lookup.com is not affiliated with the Drug Enforcement Administration. This guide is general information, not legal or compliance advice.