How Do You Read an Eligibility Response (271)?
Read a 271 in a fixed order: any error segment first, then whether the patient matched, then the status and dates for the visit date, then the plan and payer, then the benefit and cost-share lines, and last any message or other-payer lines. A response that skips that order is how an inactive or wrong-plan patient gets seen.
Written by Salman Saeed, CEO and Co-Founder · Reviewed by a Certified Medical Coder · 
In short: a 271 is the plan's answer to your 270 inquiry. It can reject the request, match the patient, report coverage dates, name the plan and list benefits, and it never promises payment. CMS's public Medicare guide shows the pieces, and commercial plans fill in the same pieces differently.
What Is a 271 Eligibility Response?
A 271 is the electronic answer a health plan sends back to a provider's 270 eligibility inquiry. Together the two make up the 270/271 transaction, which 45 CFR 162.1202 names as the standard for eligibility inquiries. The response covers eligibility, coverage and benefits, and each plan decides how much benefit detail it fills in.
One limit applies to every response. CMS states that a 271 should not be read as a promise of payment, because payment stays subject to plan terms, limits, conditions, exclusions and the member's eligibility when the service is given. The X12 implementation guide is licensed, so this post draws on CMS's public Medicare guide and X12's public code list, and your clearinghouse or payer can show the layout for other plans.
In What Order Should You Read It?
- Error segments. An AAA segment means the plan rejected the request. It does not mean the patient has no coverage.
- Patient match. Check that the name, date of birth and member ID returned match what you sent and what is on the card.
- Status and dates. Find the status element and the date segment, and test whether the visit date falls inside them.
- Plan and payer. Identify the plan type and the payer name and address, since that decides where the claim goes.
- Benefits for your service. Find the lines for your service type and read the amounts.
- Messages and other payers. Read free-text messages and any line that names another payer.
- Save it. File the response, or a screenshot, with the account.
CMS's own advice is the same in short form: trading partners should review the entire 271 response to determine the eligibility status, not only the first line.
What Do the Error Codes in a 271 Mean?
They mean the inquiry failed, usually because of data you sent. CMS's HETS guide lists the AAA reject reasons for Medicare. Fix the input and resend before you tell anyone the patient is uninsured.
| AAA03 code | When HETS returns it | Likely fix |
|---|---|---|
| 58 | Date of birth and first name are both missing | Add them from the card and ID |
| 62 | Date of service is more than four years back or four months ahead | Use a date inside that window |
| 71 | Date of birth does not match the Medicare record | Compare the card and ID, and ask the patient |
| 72 | Member ID is invalid, cannot be matched, or is missing | Re-key the MBI, and never send the old claim number |
| 73 | Last or first name does not match the matching algorithm | Use the name exactly as the card shows it |
Other payers send their own reject reasons. The principle is the same: a reject means correct and resend. A reject that repeats after correction means the patient needs to call the plan. The CO-16 code page covers what the claim looks like if bad data goes through instead.
How Do You Tell Whether Coverage Is Active on the Visit Date?
Find the status element and its dates, then check the visit date against them. In CMS's Medicare examples, a coverage line with status 1 means an entitlement period, carried with a date segment that gives the beginning and, where it applies, the end date. A line with status 6 means the patient is not eligible: CMS returns 6 without dates when Part A or Part B entitlement had not yet begun, or had ended, before the requested date.
A Medicare Advantage enrollee is returned with status U, and CMS strongly recommends contacting the plan to confirm its eligibility information. If the patient has died, a request for a date of service after the date of death returns status 6 with service type 30.
You ask about a visit on March 10, 2027 and the response shows:
What Is a Service Type Code and Which Ones Matter?
A service type code, in the EB03 element, says which kind of care a benefit line is about. X12 publishes the list publicly. When you ask for code 30, plan coverage and general benefits, a Medicare response returns the coverage status for a long list of related types, so one request often answers the rest.
| Code | X12 public name | When it matters |
|---|---|---|
| 30 | Plan coverage and general benefits | The default ask; start here |
| 1 | Medical care | Professional visits and general medical services |
| 47 | Hospitalization | Inpatient and outpatient hospital services |
| 86 | Emergency services | Emergency department benefits |
| UC | Urgent care | Urgent care visit benefits |
| MH | Mental health | Behavioral health visits |
Ask for the code that matches the service. If the response returns only general benefits and the visit is a specialty procedure, call the plan or open its portal for the service-specific lines.
Where Are the Deductible, Copay and Coinsurance?
They are in the benefit lines, each with an amount or a percentage and a time period. CMS's Medicare examples label the pieces: the line's amount element holds a dollar amount such as a deductible, the percentage element holds the coinsurance rate, and the same line appears twice when the plan reports both the base amount and the amount remaining.
Always take the remaining deductible, not the base deductible, when you quote the patient. The amount the patient owes after the plan pays posts to the claim as patient responsibility. PR-1 is the deductible and PR-2 the coinsurance, and a copay and coinsurance are quoted separately at the desk.
If the response shows a deductible but no remaining amount, ask the plan before telling the patient what is owed. A wrong quote at the desk is a bad debt later.
How Does a 271 Show Another Payer?
A response that names another payer ahead of this one is a reason to stop and check the order. CMS's Medicare examples show a Secondary Payer line with a status of R, the insurance type code, a policy number, a group number or date of loss, an enrollment date, an ongoing responsibility indicator and the payer's address. CMS tells providers to use the ongoing responsibility indicator and the case dates to decide billing for the no-fault, liability and workers' compensation types.
Coordination of benefits explains which plan pays first, and the eligibility checklist places the 271 in the front-desk routine. For the denials that follow when this step is skipped, use the denial management playbook.
How Nucleus Align Handles It
Our eligibility verification team runs automated checks and sends only the exceptions for a person to read, and we send claims within 24 hours of charge entry. Book a call to set up your checks, or visit the blog.
- HETS 270/271 5010 Companion Guide, version 15-1 · CMS
- Service type codes · X12
- 45 CFR 162.1202 Standards for eligibility for a health plan · eCFR
- 45 CFR 162.1201 Eligibility for a health plan transaction · eCFR
- Checking Medicare Eligibility (MLN8816413) · CMS
We check every rule, code and deadline against the official source. See our editorial policy.
Common Questions
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01How do you read an eligibility response (271)?
Read errors first, then the patient match, the status and dates against the visit date, the plan and payer, the benefit lines for your service type, and last any messages or other-payer lines. Review the whole response, not only the first line, and save a copy with the account.
02What does status 6 mean in a Medicare 271?
In CMS's HETS guide, status 6 means the patient is not eligible. HETS returns it without dates when Part A or Part B entitlement had not begun or had ended before the requested date of service. It can also come with dates when the patient is ineligible for part of the requested period.
03Does an AAA error mean the patient has no insurance?
No. An AAA segment means the plan rejected the request, often because the member ID, name or date of birth did not match. Correct the data from the card and resend before concluding anything. A repeated reject after correction means the patient should contact the plan.
04Is the 271 a promise that the claim will be paid?
No. CMS's HETS disclosure says the 271 response should not be read as a promise of payment. Payment stays subject to the plan's terms, limits, conditions and exclusions, and to the member's eligibility on the date of service, so quote the patient from the benefit lines and keep the copy.
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