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On HIPAA, Klaviyo vs Mailchimp is a tie, because Klaviyo's Acceptable Use Policy bars “medical records or health information, including Protected Health Information,” and Mailchimp's Data Processing Addendum says customers will not provide “Sensitive Data,” which it defines to include “employment, financial, credit, genetic, biometric or health information” (Klaviyo; Mailchimp). For a health brand, the choice between them comes down to features you can use with lists that carry no health details, plus a HIPAA email provider for anything that is PHI. Curve Compliance, which measures ad conversions for health brands without sending health data to ad platforms, checked both vendors' terms on November 9, 2026.
Book a call. Running email next to paid ads for a health brand? Curve Compliance sends conversions server-side with neutral event names and a fixed list of fields, strips PHI before data reaches an ad platform and signs a BAA on every plan. Curve's team does the setup, typically live in about a week. Book a call with Curve.
What each one's terms say about health data
Every cell below quotes the vendor's own page, opened November 9, 2026.
| Klaviyo | Mailchimp | |
|---|---|---|
| Health data in its terms | “You may not solicit, store, process, send, or transmit any of the following types of data or information in the Klaviyo platform,” including “(b) medical records or health information, including Protected Health Information as defined in the Health Insurance Portability and Accountability Act” (Acceptable Use Policy) | “Customer will not provide (or cause to be provided) any Sensitive Data to Mailchimp for processing under the Agreement,” and Sensitive Data includes “employment, financial, credit, genetic, biometric or health information” (Data Processing Addendum) |
| HIPAA in its terms | Protected Health Information is named in the Acceptable Use Policy | “If you're subject to regulations (like HIPAA) and you use the Service, then we won't be liable if the Service doesn't meet those requirements” (Terms of Use) |
| Curve's BAA Directory | Does not sign a BAA | Does not sign a BAA |
| How open tracking works | Not covered on the pages checked | “we embed a tiny invisible graphic in the bottom of your HTML email” (Mailchimp help) |
Because both sets of terms bar health information, plan for either platform on the assumption that no patient data goes in. For each vendor alone, see is Klaviyo HIPAA compliant and is Mailchimp HIPAA compliant.
What a health brand can still send
Plenty of health marketing carries no PHI: a general newsletter to everyone who signed up on your site, a product launch, educational content or a seasonal offer. The risk starts when a list, segment or trigger says something about a person's health, such as a segment built from a symptom quiz, a list of patients, or a flow fired by a prescription refill.
For a HIPAA covered entity, a list of patients ties names and emails to the fact of their care, which is the kind of information HIPAA protects: individually identifiable health information includes information that relates to “the provision of health care to an individual” (45 CFR 160.103). Marketing to that list follows the HIPAA marketing rule; see the HIPAA marketing rule and its exceptions. DTC brands outside HIPAA still have the vendors' terms to follow, and Klaviyo's bars health information whether or not HIPAA applies to you. Whether HIPAA applies to your brand at all is a question to talk to your counsel about.
Email tracking pixels and health data
Mailchimp explains how open tracking works: “When open tracking is enabled, each time you send an email campaign through Mailchimp, we embed a tiny invisible graphic in the bottom of your HTML email. This open tracker graphic, or web beacon, is unique to each email you send” (Mailchimp). So an open is a record that a specific person opened a specific campaign. If the campaign is about a condition, that record says something about the person's health.
Keep campaign names, subject lines and link parameters free of condition names, and don't build segments from health answers. Mailchimp also notes that “Open rate tracking relies on images, so it isn't 100% accurate” (Mailchimp), which is one more reason to judge email by bookings, not opens.
HIPAA email alternatives
For email that is PHI, such as appointment follow-ups or newsletters built from your patient list, use an email provider that signs a BAA and keep it separate from your marketing platform. See HIPAA compliant email providers, the BAA status of 12 email marketing platforms and HIPAA compliant marketing automation.
Measuring email-driven bookings without PHI
You can still see which emails lead to booked visits. Tag email links with UTM parameters that carry no health details, such as a campaign name like november-newsletter rather than a condition, and measure the booking on your site rather than the open.
On the site, Curve Compliance records each booking as a neutral conversion. When a visitor leaves to book in IntakeQ, Calendly, Acuity, Jane App or another scheduler, Curve keeps the ad attribution, and bookings made days later still match. With Curve Forms, every lead arrives in the Leads inbox with its answers, UTMs and ad click ID, so the UTMs show which email or ad brought each lead in.
How Curve Compliance helps
Curve Compliance covers the ad side of a health brand's marketing. It replaces browser ad pixels with one script and sends conversions server-side from Curve's servers to Meta, Google Ads, TikTok, Microsoft Advertising and LinkedIn. Each platform receives only a fixed list of fields, events can use neutral names, and contact identifiers are off by default on Meta, Google Ads and TikTok. Curve checks every event for PHI-like patterns and strips PHI before data reaches an ad platform, and Event Logs show what Curve sent and what each platform accepted.
Campaign Reporting puts Meta and Google Ads spend next to Curve-tracked conversions per campaign. Curve is SOC 2 Type II, signs a BAA on every plan, and its team does the setup, typically live in about a week.
Sources, checked November 9, 2026: Klaviyo Acceptable Use Policy; Mailchimp Data Processing Addendum, Standard Terms of Use, About Open Tracking and About Open and Click Rates; 45 CFR 160.103 (eCFR, current as of November 5, 2026).
Frequently Asked Questions
Is Klaviyo or Mailchimp better for healthcare?
On HIPAA neither is better, because both bar health information in their terms (Klaviyo; Mailchimp). Choose on features for lists that carry no health details, and use a HIPAA email provider for anything that is PHI.
Is Klaviyo HIPAA compliant?
No. Klaviyo's Acceptable Use Policy says you may not store or send “medical records or health information, including Protected Health Information” in the platform (Klaviyo).
Is Mailchimp HIPAA compliant?
No. Its Data Processing Addendum bars Sensitive Data, including health information (Mailchimp DPA), and its terms say “If you're subject to regulations (like HIPAA) and you use the Service, then we won't be liable if the Service doesn't meet those requirements” (Mailchimp terms).
Can a telehealth brand use Klaviyo?
Only for marketing that carries no health information. Klaviyo's policy bars health information in the platform, so keep quiz answers, conditions and patient status out of lists, events and flows (Klaviyo).
Which email platforms sign a BAA?
See HIPAA compliant email providers and the BAA status of 12 email marketing platforms for current lists.
Can email open tracking expose PHI?
It can. Mailchimp says its open tracker graphic “is unique to each email you send” (Mailchimp), so an open ties a person to a campaign, and a campaign about a condition says something about their health.
Does Curve Compliance sign a BAA?
Yes, on every plan. Curve sends ad conversions server-side with a fixed list of fields and strips PHI before data reaches an ad platform.
Talk to Curve Compliance
Book a call. Want email and ads measured without health data reaching ad platforms? Curve's team will review what your website sends to Meta, Google and TikTok with you and set up server-side conversions with neutral event names, under a BAA on every plan. Book a call with Curve.