Fundamentals Updated May 19, 2026

What's Actually Covered as "Preventive" Under the ACA

The ACA's $0 preventive coverage is real. So are the four conditions that have to hold for it to apply. What's covered, what gets billed, and how to appeal.

At a glance

The Affordable Care Act requires most health plans to cover specific preventive services at $0 to the patient. No copay, no coinsurance, no deductible. The list is real and large. The conditions for that $0 cost are also real, and most patient surprise bills happen when one of those conditions quietly fails.

Disclaimer

This article is general educational content and is not medical, legal, tax, or financial advice. Plan rules, federal regulations, and state laws change, and coverage outcomes depend on your specific plan, provider, diagnosis, and circumstances. CPT codes, dollar amounts, and percentages referenced here are illustrative examples drawn from public sources, not quotes for any particular plan or patient. Before making decisions about your care, coverage, or any appeal, consult a qualified professional (your insurer's member services, your benefits administrator, a healthcare attorney, or your physician, as appropriate). Use this information at your own risk.

The basic rule (Section 2713)

Section 2713 of the ACA requires non-grandfathered group and individual health plans to cover a defined list of preventive services without cost-sharing. No copay. No coinsurance. No deductible. The bill at the visit is supposed to be zero.

The defined list comes from three federal sources, covered below. It includes the annual wellness visit, screenings for cancers (colon, cervical, breast, lung in specific populations), childhood immunizations, the standard adult vaccine schedule, contraception, depression and anxiety screening, and dozens of other services. The list is updated each year as the underlying recommendation bodies issue new guidance.

The promise is straightforward in concept. The execution involves four conditions, each of which can break.

The four conditions for zero-cost coverage

For a preventive service to actually cost you $0, all four of these must be true:

  1. The service is on the official list. If your provider performed something that is not on the USPSTF, ACIP, or HRSA list (defined below), the ACA's $0 mandate does not apply.
  2. The provider is in-network. Out-of-network providers can charge whatever they charge. The ACA mandate runs through your plan's network. HealthCare.gov is explicit on this.
  3. The preventive service is the primary purpose of the visit. This is the condition that catches most patients. If the visit started as preventive but pivoted to evaluation of a separate problem, the problem-oriented portion is billed under your deductible. More on this below.
  4. Your plan is not exempt. A handful of plan categories sit outside the ACA preventive rule entirely.

Four conditions. All four must hold. Failure of any one moves you back into deductible territory.

The three official preventive services lists

The "preventive list" is actually three lists, maintained by three federal bodies:

  • The U.S. Preventive Services Task Force publishes grade-A and grade-B recommendations for screening and counseling. Examples: colorectal cancer screening for adults 45 to 75, cervical cancer screening at recommended intervals, statin use for adults at elevated cardiovascular risk.
  • The Advisory Committee on Immunization Practices (ACIP) maintains the routine immunization schedule, including the standard childhood series, HPV, shingles, flu, and COVID-19.
  • The Health Resources and Services Administration (HRSA) publishes preventive services guidelines for women (contraception, well-woman visits, screening for intimate partner violence) and for children (newborn screening, developmental screening, vision, and hearing).

The KFF ACA Preventive Services Tracker is the single best place to check whether a given service is on one of these three lists, updated for the current plan year.

Plans that are exempt entirely

Not every plan in the US has to follow Section 2713. The exemptions:

  • Grandfathered plans. A "grandfathered" plan is one in existence on March 23, 2010 (when the ACA was signed) that has not significantly changed its terms since. These plans are exempt from many ACA requirements, including preventive cost-sharing. The grandfathered share has shrunk every year and now covers a small minority of insured workers.
  • Short-term limited-duration plans. Non-ACA-compliant plans sold for coverage gaps. They can exclude preventive services, exclude pre-existing conditions, and impose dollar limits. The 2024 federal rule cut the maximum duration to four months. Older plans sold before that change can still be in force.
  • Health-sharing ministries. Faith-based cost-sharing arrangements operating outside the ACA framework. They are not insurance, are exempt from ACA mandates, and have no obligation to cover any preventive service.

If your coverage is one of these, the rules in this piece largely do not apply. Confirm before you assume.

The preventive-to-diagnostic switch

This is the single most common cause of "I thought my annual was free" bills.

Here is the mechanic. You go in for a screening colonoscopy. Per USPSTF, this is a recommended preventive service for adults age 45 and over (grade A for ages 50 to 75, grade B for ages 45 to 49, both qualifying for $0 cost-sharing under the ACA). Your colonoscopy itself is $0.

The gastroenterologist finds a polyp and removes it during the same procedure. The removal and the pathology on the polyp are diagnostic, not screening. Diagnostic services are not on the USPSTF preventive list. They run through your deductible and coinsurance.

CMS, the Department of Labor, and Treasury addressed this scenario in ACA Implementation FAQ Part 12, issued in 2013, with a related anesthesia clarification in subsequent FAQ guidance. The short version: if a colonoscopy starts as screening and turns into a polyp removal, the agencies told payers to treat the procedure itself as part of the screening (so the colonoscopy stays $0). Anesthesia, pathology fees, and follow-up testing may still be billed separately and may not be protected in every plan. Patient-side bills for "free" colonoscopies have been a documented and recurring pattern over the past decade.

The same logic applies to:

  • Mammograms that surface a finding and require diagnostic follow-up imaging.
  • Annual physicals that surface a separate problem the doctor evaluates during the same visit.
  • Lab panels run for screening that produce a finding requiring a repeat test under a diagnostic code.

The pattern repeats. The screening test is on the preventive list. The follow-up usually is not.

Common services patients assume are covered but might not be

A few specific traps:

  • Anesthesia for colonoscopies. Some plans cover the screening colonoscopy and related anesthesia at $0. Others apply cost-sharing to the anesthesia separately, especially when the anesthesia provider bills under their own NPI and is out-of-network. Verify both with the plan before scheduling.
  • Diagnostic follow-up after a screening finding. If your mammogram is abnormal and you need an ultrasound or biopsy, the follow-up is diagnostic. Some states have passed laws requiring follow-up breast imaging to be covered at $0. Most have not. Check your state.
  • Out-of-network providers at in-network facilities. A hospital-based pathologist or anesthesiologist outside your plan network can balance-bill in some scenarios. The No Surprises Act blocks balance billing in many of these situations but does not change cost-sharing for non-emergency, scheduled care if you knowingly chose the out-of-network provider.
  • Counseling vs. medication. A USPSTF recommendation might cover counseling for tobacco cessation. The actual prescription medication might be covered, or might run through the formulary at standard cost-sharing.
  • Provider-coded "office visit" alongside preventive. See Modifier 25 Explained.

The HealthCare.gov page itself includes the caveat that $0 cost is "in some cases" and depends on plan and provider. It is worth reading the page in full before assuming any specific service will be free.

How to verify before your visit

Three steps that take ten minutes.

  1. Find the service on the KFF ACA Preventive Services Tracker. Confirm it is on one of the three official lists (USPSTF, ACIP, HRSA) and note the exact age and population for which it is covered.
  2. Call your insurer's member services line. Ask: "Is CPT code [X] covered as preventive at $0 cost-sharing under my plan, for my age and sex, performed by [provider name, in-network]?" Get a reference number for the call.
  3. Read your Summary of Benefits and Coverage for the section on preventive care exclusions. Some plans note specific exclusions or limits the federal list does not.

If the answer at step two is yes and a bill arrives anyway, the call reference number is your appeal evidence.

How to appeal a billed "preventive" service

The basic playbook:

  1. Request an itemized bill. Get the line-item list with CPT codes, modifiers, and diagnosis codes. An EOB summary alone is not enough.
  2. Identify which line items are coded as preventive vs. diagnostic. Preventive CPT codes for adult wellness include 99381 through 99387 (initial preventive medicine, new patient) and 99391 through 99397 (periodic preventive medicine, established patient). Compare the diagnosis codes attached to each line.
  3. File an internal appeal with your insurer. State the specific ACA preventive service you believe applies. Cite the USPSTF, ACIP, or HRSA listing and the date of the recommendation. Attach the call reference if you have one.
  4. If denied internally, file for external review. Most ACA-compliant plans must offer access to an independent external review process. KFF data on ACA marketplace plans in 2024 shows about 34% of internal appeals get overturned, and the appeal rate is under 1%. The math is brutal in your favor if you actually file.

Most patients who get billed pay without appealing. The reason is rarely that the case is weak. It is that the process is exhausting and the timeline is long. If you believe a charge was misclassified and the dollar amount justifies the time, consider appealing or requesting an itemized review before paying.

Opinion

The ACA preventive promise is real. Tens of millions of services that used to come with copays now do not. That is a genuine policy success.

The conditions for the promise to apply are also real, and most patients only learn what they are after a bill arrives. The average patient does not know what modifier 25 is, what counts as "diagnostic" versus "screening," or that they have an appeal right at all. The information asymmetry is the actual problem. Fix it by reading your SBC, learning the four conditions, and calling your insurer before the visit instead of after the bill.

For the most common surprise-bill mechanism in this category, see Modifier 25 Explained. For the plan-type basics that determine what your network and deductible look like, see The Five Health Insurance Plan Types Explained. On the operator side, Denials 101 covers how the same rules show up from the billing perspective.

What this means for you

  1. Read the preventive care section of your SBC. Note any plan-specific exclusions before scheduling.
  2. Cross-check the service on the KFF ACA Preventive Services Tracker before the visit.
  3. Call your insurer's member line in advance. Ask the question with the specific CPT code and provider name. Get a reference number.
  4. If a "free" service gets billed, request an itemized bill and appeal. Overturn rates run around one in three for the patients who actually file.

Sources

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