How to verify a DEA number (check-digit method)
A DEA registration number has two letters followed by seven digits. The seventh digit is a check digit that you can verify by hand, which helps catch forged or mistyped numbers.
Method
- Check that the second letter matches the first letter of the prescriber's last name.
- Add the 1st, 3rd and 5th digits.
- Add the 2nd, 4th and 6th digits, then double that sum.
- Add the two results. The last digit of the total must equal the 7th digit.
Worked examples
Example 1
Dr. Nguyen writes a prescription for a Schedule II medication. Which DEA number could be valid for Dr. Nguyen?
GN5636595GG5636595GN5636598GN5366595
Show solution
- The 2nd letter should match the prescriber's last-name initial: "N".
- Add digits 1, 3 and 5: 5 + 3 + 5 = 13
- Add digits 2, 4 and 6 and double: (6 + 6 + 9) × 2 = 42
- Total = 55; the last digit (5) must equal the 7th digit.
- Valid: GN5636595
Answer: GN5636595
Example 2
Dr. Nguyen writes a prescription for a Schedule II medication. Which DEA number could be valid for Dr. Nguyen?
GN2432437GN4232437GN2432430GG2432437
Show solution
- The 2nd letter should match the prescriber's last-name initial: "N".
- Add digits 1, 3 and 5: 2 + 3 + 4 = 9
- Add digits 2, 4 and 6 and double: (4 + 2 + 3) × 2 = 18
- Total = 27; the last digit (7) must equal the 7th digit.
- Valid: GN2432437
Answer: GN2432437
Example 3
Dr. Diaz writes a prescription for a Schedule II medication. Which DEA number could be valid for Dr. Diaz?
GR3536337GD3536337GD3563337GD3536339
Show solution
- The 2nd letter should match the prescriber's last-name initial: "D".
- Add digits 1, 3 and 5: 3 + 3 + 3 = 9
- Add digits 2, 4 and 6 and double: (5 + 6 + 3) × 2 = 28
- Total = 37; the last digit (7) must equal the 7th digit.
- Valid: GD3536337
Answer: GD3536337
Tips
- Passing the check-digit test does not prove a prescription is legitimate. Follow your pharmacy's verification procedures.
- The first letter identifies the registrant type (for example A, B, F or G for many practitioners, M for mid-level practitioners).
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