The CDC does call people, and the calls are not always scams. The agency runs several large-scale telephone surveys every year, including the Behavioral Risk Factor Surveillance System (BRFSS), which contacts hundreds of thousands of adults across all 50 states, and the National Immunization Survey, which tracks childhood vaccination rates. But scammers also impersonate government agencies, and caller ID spoofing makes it trivially easy to display a fake name or number on your phone. Telling the two apart requires knowing what a real CDC survey call looks and sounds like, and what it will never ask you to do.
What the CDC Actually Calls People About
The CDC’s best-known telephone survey is the BRFSS, a network of health-related phone surveys conducted by all 50 states, the District of Columbia, and participating U.S. territories, with technical assistance from the CDC itself.1PubMed Central. National weighting of data from the Behavioral Risk Factor Surveillance System (BRFSS) – Section: BACKGROUND The data collected through BRFSS feeds into everything from state-level obesity estimates to chronic disease funding decisions. If you get a call related to this survey, it is a state health department or a contracted research organization actually placing the call on the CDC’s behalf, not a CDC employee dialing your number from Atlanta.
The National Immunization Survey (NIS) is another major one. This survey tracks vaccination coverage among children and teens, and it contacts both landline and cell-phone households. In an experiment testing different caller ID displays, researchers found that showing “CDC NATL IMMUN” on the caller ID instead of the survey contractor’s name (“NORC UCHICAGO”) led to a roughly 15 percent increase in completed screening interviews on landlines.2PubMed Central. An Evaluation of the Impact of Using an Alternate Caller ID Display in the National Immunization Survey – Section: 3. Results In other words, people were more likely to stay on the line when they could see the call was connected to the CDC. That finding is a double-edged sword: it proves real surveys benefit from displaying their CDC affiliation, but it also means scammers have a ready-made template to exploit.
Other CDC-affiliated surveys include the National Health Interview Survey (NHIS), which is conducted in person but may involve telephone follow-ups, and various outbreak investigations where CDC epidemiologists or state health officials phone individuals who may have been exposed to a disease. Contact tracing during COVID-19 introduced millions of Americans to this kind of call for the first time, and the confusion it created has not fully faded.
What a Legitimate Survey Call Looks Like
A genuine CDC-affiliated survey call follows a predictable script. The interviewer identifies the survey by name, names the organization conducting it, and explains that participation is voluntary. They ask questions about health behaviors, vaccination history, or chronic conditions. They do not ask for your Social Security number, bank account details, Medicare number, or any form of payment. They will not threaten you with arrest, fines, or loss of benefits if you decline to participate. And they will not pressure you to make a decision on the spot about anything financial.
Many legitimate surveys now send an advance letter or postcard before calling. A meta-analysis of telephone survey methods found that advance letters boosted average response rates from about 58 percent to 66 percent and cooperation rates from about 64 percent to 75 percent.3Public Opinion Quarterly. The Influence of Advance Letters on Response in Telephone Surveys: A Meta-Analysis Separate research confirmed that sending letters is actually more cost-effective than sending postcards, which in turn is more effective than sending nothing at all.4Public Opinion Quarterly. The Cost-Effectiveness of Alternative Advance Mailings in a Telephone Survey So if you received a letter in the mail a week or two before the call, mentioning a specific survey name and providing a callback number you can verify independently, that is a strong signal the call is real. Scammers rarely bother with the postal system because it is slow, expensive, and creates a paper trail.
If you are caught off guard and did not receive a letter, you can ask the caller for the survey name, their supervisor’s name, and a phone number to call back. A legitimate interviewer will give you all three without hesitation. You can then look up the survey independently on the CDC’s website or call the state health department to confirm. A scammer will resist this because the whole scheme depends on keeping you on the line.
How Scammers Impersonate Government Agencies
The core tool is caller ID spoofing, which lets anyone display whatever name and number they want on an outgoing call. The technology is cheap and widely available. Research into real-time spoofing detection has documented how straightforward it is to forge caller identification information on both internet-based and traditional phone networks.5ACM Transactions on Privacy and Security. Spoofing Against Spoofing: Toward Caller ID Verification in Heterogeneous Telecommunication Systems A scammer can make “CDC” or “Centers for Disease Control” appear on your screen in a matter of seconds, and the number displayed can be a legitimate CDC number cloned from the agency’s public directory.
The typical government-impersonation scam follows a pattern. The caller claims there is a problem: an unpaid fine, a quarantine violation, an issue with your insurance, a warrant related to your health records. The language is designed to trigger urgency and fear. From a psychological standpoint, this works because compliance tends to emerge when the perceived authority and power of the caller override the target’s personal judgment. Symbolic authority cues, like naming a federal agency, combined with escalating threats, reinforce the belief that going along is the safest option.6PubMed Central. Digital arrest in the cyber age: a psychological perspective on fear, authority, and consciousness – Section: Mechanisms and stages of digital arrest The scammer’s goal is to keep you in that heightened state long enough to extract money (often via gift cards or wire transfers) or personal information.
Some scams are more subtle. Instead of threatening you, the caller conducts what feels like a normal health survey but weaves in questions about your insurance, Medicare number, or date of birth. By the end, you have handed over enough information for identity theft while thinking you were just helping with public health research. These are harder to spot because the format mimics a real survey.
Red Flags That Separate Scams from Surveys
A few concrete differences can help you sort a legitimate call from a fraudulent one:
- Money: A real CDC survey never asks for payment of any kind. No fines, no fees, no “processing charges.” If money comes up, hang up.
- Threats: Legitimate interviewers make clear that participation is voluntary. If the caller says you will be arrested, fined, or lose benefits for not answering, it is a scam.
- Personal identifiers: A genuine health survey may ask your age, race, or zip code for demographic purposes, but it will not ask for your Social Security number, bank account number, or Medicare ID.
- Time pressure: Real survey interviewers will let you call back later or schedule a different time. Scammers insist you stay on the line and resolve the “issue” immediately.
- Callback verification: A legitimate caller will provide a verifiable phone number and encourage you to confirm the survey’s existence on your own. A scammer will discourage you from hanging up and calling back.
One tricky area is the callback number itself. Because of caller ID spoofing, even if the number displayed on your phone matches one listed on the CDC’s website, that does not guarantee the call originated there. The safest approach is to hang up, find the number independently through an internet search or by calling your state health department directly, and then call that number yourself. If the survey is real, they will have a record of your household in their system.
Why Response Rates Have Cratered and Why That Matters
The scam problem sits inside a larger crisis for telephone-based public health research. Response rates for phone surveys have plummeted into the single digits in many cases, driven partly by the flood of robocalls that makes people reluctant to pick up unknown numbers at all.7Journal of Survey Statistics and Methodology. Telephone Sample Surveys: Dearly Beloved or Nearly Departed? Trends in Survey Errors in the Era of Declining Response Rates One epidemiological study that tracked call outcomes found that even among people who answered the phone, only about 55 percent agreed to participate, and the overall response rate for total calls placed was around 45 percent.8PubMed Central. Analysis of Factors Influencing Telephone Call Response Rate in an Epidemiological Study – Section: 3. Results
That creates a vicious cycle. When fewer people answer, the data gets less representative. Researchers try harder to reach people, which means more call attempts and more money spent per completed interview. Meanwhile, the very scams that erode trust are themselves fueled by the same cheap calling technology that researchers rely on. The CDC and its survey contractors have tried to fight back by displaying recognizable caller ID names, but as the NIS experiment demonstrated, that tactic mostly helped on landlines, where the displayed name boosted completion rates, while the effect on cell phones was negligible.2PubMed Central. An Evaluation of the Impact of Using an Alternate Caller ID Display in the National Immunization Survey – Section: 3. Results Given that most Americans now rely on cell phones as their primary line, this is a shrinking tool.
The shift toward cell-phone-only households has been dramatic. Between 2003 and 2009 alone, the share of U.S. adults living in cell-phone-only households jumped from under 3 percent to about 25 percent, and it has continued climbing since.9PubMed Central. Integrating a Multimode Design Into a National Random-Digit–Dialed Telephone Survey – Section: BRFSS Multimode Designs Pilot studies showed that excluding cell-phone-only households significantly biased results for nine of 16 key health indicators, because these households skew younger, more male, and more racially diverse. Reaching cell-phone users costs more, too, partly because federal law requires manual dialing of cell numbers rather than automated dialers. All of this means the CDC’s surveys are getting more expensive and harder to run at exactly the moment public trust in unknown callers is at its lowest.
STIR/SHAKEN and Whether Technology Can Fix This
The Federal Communications Commission has mandated that U.S. telecom providers implement a system called STIR/SHAKEN, which uses digital signatures to verify that a call actually originates from the number it claims to come from. The idea is that your phone or carrier can check whether the calling number has been authenticated and flag calls that have not been. In theory, this would make caller ID spoofing much harder.
In practice, the system has significant gaps. STIR/SHAKEN only works on internet-based phone systems, leaving older, non-IP networks unprotected. Scaling the underlying infrastructure for the entire global telecom industry has proven extremely difficult.5ACM Transactions on Privacy and Security. Spoofing Against Spoofing: Toward Caller ID Verification in Heterogeneous Telecommunication Systems Many scam calls originate overseas on networks that do not participate in the STIR/SHAKEN framework at all, so those calls can still arrive with spoofed IDs. And even domestically, smaller carriers have been slow to implement the standard. You may see “Verified Caller” or a checkmark on some calls from compliant carriers, but the absence of that indicator does not necessarily mean the call is fraudulent. It might just mean the call passed through an older network along the way.
For the CDC’s surveys, STIR/SHAKEN could eventually help by giving authenticated calls a visual trust signal on the recipient’s phone. But that future is patchy right now, and relying on your phone’s spam filter or carrier verification alone is not a substitute for the behavioral red flags described above.
The Cost of Getting This Wrong in Both Directions
There are real consequences to both ignoring a legitimate CDC survey and falling for a scam. On the survey side, telephone-based follow-ups already cost significantly more than mail-based approaches. One study comparing strategies found that telephone interviews cost about $53 per completed survey when a signed consent form was required, versus $27 per completed survey for a reminder-call approach that directed people back to a mail questionnaire. Applying the more expensive interviewing strategy across an entire study sample would have increased costs by 137 percent.10PubMed Central. Telephone follow-up to a mail survey: when to offer an interview compared to a reminder call – Section: Results Every person who hangs up on a legitimate survey because they assume it is a scam drives those costs higher and makes the resulting data less representative of the actual population.
On the scam side, the Federal Trade Commission reports that government-impersonation fraud costs Americans hundreds of millions of dollars per year, with the median individual loss running into the thousands. Older adults are disproportionately targeted, though younger adults actually report more total fraud incidents. The emotional toll also matters. People who have been scammed often feel ashamed and become less willing to engage with any phone communication afterward, which further erodes survey participation.
The two problems feed each other. Scams make people distrust legitimate calls, which forces survey operations to spend more money and use more aggressive follow-up strategies (multiple callbacks, advance mailings, mixed-mode approaches), which in turn makes the survey landscape noisier and gives scammers more templates to imitate.
What to Do If You Think the CDC Is Calling
If your phone rings and the display says something related to the CDC, a state health department, or a survey contractor name you do not recognize, you do not have to make a snap decision. Let the call go to voicemail. A legitimate survey operation will leave a message identifying the survey, the organization conducting it, and a number you can call back. Scammers sometimes leave voicemails too, but theirs tend to include urgency cues like “call back within 24 hours to avoid legal action,” which no real survey would ever say.
If you do answer, listen for the hallmarks of a real survey: the interviewer names the specific study, explains it is voluntary, and asks health-related questions rather than financial ones. If at any point you feel pressured, confused, or asked for something that does not fit a health survey, hang up. You can always call the CDC’s general information line (800-232-4636) or your state health department to verify. If the call was legitimate, they will confirm it and can often schedule a callback at a time that works for you.
Participating in legitimate CDC surveys, when you have confirmed they are real, genuinely matters. These are not marketing calls dressed up in government clothing. The data shapes vaccination policy, chronic disease funding, and emergency response planning. The BRFSS alone provides the primary source of state-level data on health behaviors for most of the country. When response rates drop, the picture of the nation’s health gets fuzzier, and the people most affected are often the communities already underserved by the healthcare system.
When the CDC Contacts You by Means Other Than Phone
Phone calls are not the only way the CDC or its partner agencies might reach you. During disease outbreaks, contact tracers may send text messages or emails, and some surveys have moved to web-based or mail-based formats to compensate for falling phone response rates. The BRFSS itself has piloted multimode designs combining mail, web, and phone to reach the cell-phone-only and hard-to-reach populations that landline surveys miss.9PubMed Central. Integrating a Multimode Design Into a National Random-Digit–Dialed Telephone Survey – Section: BRFSS Multimode Designs
Scammers have followed this expansion. Phishing emails that claim to be from the CDC, text messages about fake quarantine orders, and even fake CDC websites have all been documented. The same principles apply across every channel: a legitimate contact will never demand money, threaten legal action, or ask for financial account details. If a text message includes a link, do not click it. Navigate to the CDC’s website directly by typing the address into your browser. And remember that the CDC will never ask you to download software, grant remote access to your computer, or pay for a “health clearance certificate.” If any of those come up, you are dealing with a scam regardless of how official the message looks.
Afternoon calls, incidentally, tend to get better results for real surveys. The epidemiological study tracking call outcomes found that response rates roughly doubled from morning to afternoon, jumping from about 42 percent to nearly 69 percent.8PubMed Central. Analysis of Factors Influencing Telephone Call Response Rate in an Epidemiological Study – Section: 3. Results Legitimate survey operations tend to schedule calls during times when people are more likely to be available and receptive. Scammers, by contrast, often operate from overseas time zones and may call at odd hours, though this is far from a reliable distinguishing factor on its own.