DEA Number Calculation: How to Check and Calculate DEA Numbers Step by Step
Learn how to dea number calculation with step-by-step guidance and practical examples for your workflow.
Eoin McMillan
January 29, 2026 • 11 min read
A DEA number is a unique identifier for prescribers of controlled substances, and its last digit is validated with a checksum. To check a DEA number, add the 1st, 3rd, and 5th digits; add twice the sum of the 2nd, 4th, and 6th digits; then compare the rightmost digit of this total to the DEA number’s last digit.
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What is a DEA number and what is it used for?
A DEA number, issued by the Drug Enforcement Administration, is a unique identifier required for healthcare practitioners who prescribe, dispense, or administer controlled substances. According to official DEA guidance, this number is essential for tracking controlled substances and preventing abuse. It is used in prescription processing, pharmacy records, and regulatory compliance to ensure that only authorized individuals handle these medications.
Data from regulatory resources explains that DEA numbers help maintain accountability in the pharmaceutical supply chain. Pharmacies and hospitals must verify DEA numbers before dispensing controlled substances to comply with federal laws. Research on prescription safety highlights the importance of DEA validation in reducing medication errors and fraudulent prescriptions.
DEA number format and components
A standard DEA number consists of two letters followed by seven digits. The format is typically represented as XX1234567, where:
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First letter: Indicates the type of registrant (e.g., 'A' for physician, 'B' for hospital, 'M' for mid-level practitioner).
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Second letter: Usually the first letter of the registrant's last name.
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Digits 1 to 6: A unique serial number assigned to the registrant.
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Digit 7: The checksum digit, calculated from the first six digits to validate the number.
According to the DEA's Analysis of Drugs Manual, this structured format ensures uniqueness and allows for easy verification through the checksum algorithm.
DEA Number Format Breakdown
| Component | Description | Example |
|---|---|---|
| First Letter | Registrant type (e.g., A, B, M) | A |
| Second Letter | First letter of registrant's last name | S |
| Digits 1-6 | Unique serial number | 123456 |
| Digit 7 | Checksum digit | 9 |
How to calculate a DEA number checksum?
The DEA number checksum digit is calculated using a modular arithmetic formula. This validation ensures that the number is correctly formatted and not tampered with. Here are the steps to compute the checksum:
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Extract the six digits: From the DEA number, take the six digits after the two letters (positions 1 to 6).
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Apply the formula: Use the checksum algorithm described below.
2026 compliance recommendations stress verifying identifiers before dispensing, making this calculation crucial for pharmacy professionals.
Step 1: Extract the Digits
From the DEA number (e.g., AB1234567), ignore the two letters and focus on the first six digits: 1, 2, 3, 4, 5, 6. The seventh digit is the checksum to be verified.
Step 2: Sum the Odd Positions
Add together the digits in the 1st, 3rd, and 5th positions. For example, with digits 1,2,3,4,5,6: 1st digit=1, 3rd digit=3, 5th digit=5. Sum = 1 + 3 + 5 = 9.
Step 3: Sum and Double the Even Positions
Add the digits in the 2nd, 4th, and 6th positions, then multiply the sum by 2. For digits 1,2,3,4,5,6: 2nd digit=2, 4th digit=4, 6th digit=6. Sum = 2 + 4 + 6 = 12. Double: 12 * 2 = 24.
Step 4: Combine the Totals
Add the result from step 2 and step 3. In our example: 9 + 24 = 33.
Step 5: Extract the Rightmost Digit
Take the rightmost digit (units place) of the total from step 4. For 33, the rightmost digit is 3.
Step 6: Compare to Checksum Digit
Compare this digit to the seventh digit (checksum) of the DEA number. If they match, the DEA number is valid. In our example, the seventh digit is 7, but we got 3, so AB1234567 is invalid. A valid number would have a checksum that matches.
Worked examples of DEA number validation
Let's apply the checksum calculation to real-world examples to ensure understanding.
Example 1: DEA Number AP1234563
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Digits: 1,2,3,4,5,6 (checksum digit is 3)
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Step 1: Sum odd positions: 1 + 3 + 5 = 9
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Step 2: Sum even positions: 2 + 4 + 6 = 12; double: 12 * 2 = 24
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Step 3: Total: 9 + 24 = 33
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Rightmost digit: 3
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Comparison: Checksum digit is 3, so valid.
Example 2: DEA Number BS9876542
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Digits: 9,8,7,6,5,4 (checksum digit is 2)
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Step 1: Sum odd positions: 9 + 7 + 5 = 21
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Step 2: Sum even positions: 8 + 6 + 4 = 18; double: 18 * 2 = 36
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Step 3: Total: 21 + 36 = 57
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Rightmost digit: 7
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Comparison: Checksum digit is 2, but we got 7, so invalid.
These examples demonstrate how the checksum catches errors or fraudulent numbers.
For a visual walkthrough of DEA number validation, watch this video from Amanda PharmD that covers a practice test question.
How to build a DEA number checker in Excel or a spreadsheet?
You can automate DEA number validation using spreadsheet formulas in Excel or Google Sheets. Here’s a step-by-step method:
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Input DEA Number: Assume the DEA number is in cell A1, formatted as text (e.g., "AP1234563").
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Extract Digits: Use the MID function to get each digit. For example, to get the first digit:
=MID(A1,3,1)(since letters are in positions 1 and 2). -
Calculate Checksum: Create formulas for the odd and even sums.
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Odd sum:
=VALUE(MID(A1,3,1)) + VALUE(MID(A1,5,1)) + VALUE(MID(A1,7,1)) -
Even sum:
=(VALUE(MID(A1,4,1)) + VALUE(MID(A1,6,1)) + VALUE(MID(A1,8,1))) * 2 -
Total:
=odd_sum + even_sum -
Rightmost digit:
=MOD(total, 10)
-
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Compare: Extract the checksum digit with
=VALUE(MID(A1,9,1))and compare to the calculated rightmost digit. Use an IF statement to display "Valid" or "Invalid".
This approach saves time and reduces manual errors, especially for bulk verification.
Legal and ethical considerations around DEA numbers
DEA numbers are sensitive identifiers that must be handled with care. According to official DEA guidance, it is illegal to use or generate DEA numbers without authorization. Generating sample DEA numbers for training purposes should only be done using mock numbers that do not resemble real identifiers to avoid compliance issues.
Data from regulatory resources emphasizes that falsifying DEA numbers can lead to severe penalties, including fines and imprisonment. Healthcare providers must verify DEA numbers through official channels and report any discrepancies. 2026 compliance recommendations stress the importance of robust validation processes to prevent prescription drug abuse and ensure patient safety.
How do you calculate the checksum for a DEA number?
To calculate the checksum, extract the first six digits after the letters. Add the 1st, 3rd, and 5th digits. Then, add the 2nd, 4th, and 6th digits and multiply the sum by 2. Add these two totals together, and the rightmost digit of this sum should match the seventh digit of the DEA number.
What is the formula for validating a DEA number?
The validation formula is: Checksum = (1st + 3rd + 5th digit) + 2*(2nd + 4th + 6th digit). The rightmost digit of the result must equal the last digit of the DEA number. If not, the number is invalid.
Can I use a DEA number calculator in Excel?
Yes, you can build a DEA number calculator in Excel using functions like MID and MOD to extract digits and compute the checksum. This automates validation for multiple numbers, saving time and reducing errors in pharmacy settings.
What do the letters and numbers in a DEA number mean?
The first letter indicates the registrant type (e.g., physician, hospital), the second letter is usually the first letter of the registrant's last name, the next six digits are a unique serial number, and the seventh digit is the checksum for validation.
Is it legal to generate sample DEA numbers for training?
It is not legal to generate realistic DEA numbers for training. Instead, use mock numbers that are clearly fictional and do not match the format of real DEA numbers to avoid legal issues and ensure compliance with regulations.
Key Takeaways
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DEA numbers have a built-in checksum digit calculated from the first six digits after the letters.
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The validation formula involves summing odd-position digits and twice the sum of even-position digits.
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Automating checksum calculation in spreadsheets can improve accuracy and efficiency for pharmacies.
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Always verify DEA numbers through official channels to comply with legal requirements.
Sources
- According to official DEA guidance, this number is essential for tracking controlled substances and preventing abuse. [Source]
- Data from regulatory resources explains that DEA numbers help maintain accountability in the pharmaceutical supply chain. [Source]
- According to the DEA's Analysis of Drugs Manual, this structured format ensures uniqueness and allows for easy verification through the checksum algorithm. [Source]
