User Did Not Receive the Code - Troubleshooting SMS Delivery

If a patient or clinician user is not receiving messages from SigmaMD, start with the channel that applies to them. Since the September 15, 2025 patient login update, a phone number is no longer required on a patient’s chart, and registration and login codes for the SigmaMD Patient App and Patient Portal are sent to the patient’s email address as the primary, guaranteed channel — SMS is only sent as an additional channel when a phone number happens to be on file. If a patient isn’t receiving a registration code, start with Step 1. If the issue involves a clinician user, or a patient who also has a phone number on file and still isn’t receiving texts, skip to Step 2.

Step 1: Check the Patient’s Email Address

Confirm that the email address listed on the patient’s chart is correct and belongs to the patient.

Ask the patient to check their spam or junk folder for the message.
Patients should contact their clinician’s practice to verify the email address on file.
If the email address is incorrect, update it in the patient’s chart, then resend the invitation code.

If the email address is correct and the code still isn’t arriving, or the affected user is a clinician, continue with the SMS troubleshooting steps below.

Step 2: Verify the Phone Number in SigmaMD

Before troubleshooting further, confirm that the phone number listed in the patient’s chart or clinician's profile is correct and SMS-capable.

Patients should contact their clinician’s practice to verify the phone number on file.
Clinicians should contact their practice administrators to verify the phone number on file.
If the number is incorrect or not SMS-capable, update the patient's number in SigmaMD. For updates to the clinician's profile number, contact support.

Step 3: Check if the Number Is SMS-Capable (VoIP or Landline Check)

Some phone numbers, especially VoIP numbers functioning as landline numbers, cannot receive SMS messages. This includes certain numbers provided by Xfinity Voice or other internet-based phone services.

Ask the user to visit this link: Carrier Lookup Tool
Enter their phone number and review the result.
If the Line Type is listed as Landline, it cannot receive SMS messages.
In this case, update the patient chart with a valid mobile number that can receive SMS. For updates to the clinician's profile number, contact support.

Step 4: Check for Message Filtering and Blocking

If the number is confirmed as mobile but messages are still not received, the issue may be related to filtering settings or spam protection.

On both iOS and Android, devices may block texts from unknown or suspected spam sources.

iPhone – Filter Unknown Senders

Go to Settings > Messages and turn off Filter Unknown Senders.

Android – Spam Protection

Go to Messaging app > Three dots > Settings > Spam Protection and disable spam filtering.

Blocked Contacts

Ensure the sender’s number is not blocked on the phone:

iOS: Settings > Messages > Blocked Contacts
Android: Messaging app > Three dots > Spam & Blocked > Blocked Numbers

Step 5: Carrier-Specific Message Blocking

Some mobile carriers have message-blocking tools that may filter or block messages.

T-Mobile

Scam Shield may block automated texts.
Disable it by dialing #632# or using the Scam Shield app.

AT&T and Verizon

These carriers use tools like AT&T ActiveArmor and Verizon Call Filter to block spam.
Review your settings in those apps or contact the carrier if needed.

If you’ve completed all the steps above and the issue persists, please reach out to our support team for further assistance.