The autocoder can add four qualifying circumstance add-on codes to an anesthesia claim: 99100 (extreme age), 99116 (total body hypothermia), 99135 (controlled hypotension), and 99140 (emergency conditions). It codes each one only from the documentation in the record.

These codes are add-ons. They never stand alone on a claim. A claim whose only surgical code is an add-on raises a HARDSTOP review alert.

## 99100 extreme age

The autocoder anchors the age test to the date of service, not to the day the case is coded. It bills 99100 when the patient is younger than 1 year, or at least 70 years and 1 day on the date of service. The 70th birthday alone does not qualify. This boundary is the rule stated in the ASA Relative Value Guide.

The autocoder does not report 99100 with the anesthesia codes 00326, 00561, 00834, or 00836. These codes already describe a patient younger than 1 year, and CPT does not allow the add-on with them. The autocoder moves such a 99100 to the bundled procedures and never adds a bypass modifier.

The autocoder does this arithmetic itself, and it raises no alert for the result. The claim carries the decision instead.

### What the claim carries

**When 99100 bills**, the rationale on the 99100 line carries the verdict. The rationale opens with "Extreme age verified on the date of service", then names the date of service and the exact age the rule used, for example "70 years 1 day".

**When 99100 does not bill**, the code stays on the claim as an entry in the bundled procedures. The reason on that entry states why: the age on the date of service does not qualify, the anesthesia code already describes the age, the payer class bundles the add-on, or the age could not be verified.

**One 99100 per anesthetic.** The extreme-age add-on is reported once per anesthetic. If the documentation produces more than one 99100, the autocoder keeps the first line and moves each further copy to the bundled procedures as a duplicate.

Every claim also records the age verdict, the input the verdict came from, and the exact age the rule used. A reviewer can read the decision without reopening the chart.

### Demographics that do not add up

If the patient's date of birth is later than the date of service, the two values cannot both be right. The autocoder raises the `patient_dob_after_dos` alert (HARDSTOP, severity 8) and withholds 99100. Correct the demographics, then reprocess the claim. Every date-anchored rule depends on those two dates, so the alert is not only about the add-on.

If a date of birth or a date of service is missing, the standard configuration raises the missing-field alert for that field, and the automatic gap fill then looks for the value in the record. When the value arrives, the autocoder runs the age test again. A patient who qualifies gets 99100 back on the billable lines. A patient who does not qualify keeps 99100 in the bundled procedures. An organization that turns off the required-field check for the missing value gets the `extreme_age_99100_unverified` alert (FINANCIAL, severity 6) instead, so a withheld add-on is never silent.

### Ask for a coder on every 99100 or 99140

Some organizations want a human to look at every extreme-age or emergency add-on. This is a facility setting, not a change in the coding. Ask your Hank representative to turn the alert on for the rule that adds the code. This is the setting for 99100:

```json
"processingRules": {
    "special_circumstances_99100": {
        "action": {
            "setBillable": true,
            "createHRE": true,
            "hreTag": "FINANCIAL",
            "hreSeverity": 4,
            "hreReviewerRole": "CODER",
            "hreTemplate": "99100 billed for an extreme-age patient - confirm the date of birth."
        }
    }
}
```

Use the same shape on `special_circumstances_99140` for the emergency add-on. Give every key: `createHRE` turns the alert on, and `hreTag`, `hreSeverity`, and `hreReviewerRole` set the type, the severity, and the suggested reviewer. `hreTemplate` is the text a coder reads.

## 99116 and 99135

The autocoder codes 99116 when the record documents deliberate total body cooling as an anesthetic technique. It codes 99135 when the record documents deliberate controlled hypotension as an anesthetic technique. The cooling and the low blood pressure that come with cardiopulmonary bypass are not the same thing, and they do not support these codes. Incidental low temperature, and hypotension treated with pressors, do not support them either.

Every 99116 or 99135 line raises the `qc_addon_review` alert (FINANCIAL, severity 5). The alert asks a coder to confirm the record documents the deliberate technique. Your facility configuration controls this rule. Contact your Hank representative to change it.

## 99140 emergency conditions

The autocoder codes 99140 when the record states an emergency: a physical status with the E suffix, such as "ASA III-E", or a statement that a delay in treatment would significantly increase the threat to the patient's life or body part. The word "emergence", the name of a department, a printed list of physical status options, and a history of an earlier emergency do not state an emergency for this case. The autocoder does not read an emergency from an anesthesia postoperative note.

The autocoder trusts that documentation and raises no alert. If your organization wants a coder to review a 99140 that rests on weak evidence, ask your Hank representative to turn on the `emergent_weak_evidence` rule (FINANCIAL, severity 5). With the rule on, the alert appears when 99140 bills and the cited documentation shows neither an E physical status nor an affirmative emergency statement.

A record that is handwritten only already raises the handwritten emergency-status alert. The evidence rule leaves those records to it.

## Payer classes

On a Medicare or Medicare Advantage claim, the autocoder moves all four codes off the billable lines and keeps them on the claim as entries in the bundled procedures. Medicare assigns these codes CMS status indicator B: they are bundled into the base anesthesia code, and Medicare never pays them separately. The reason on each bundled entry names the payer class. There is no alert, because your configuration already decided this.

Commercial, Medicaid, self-pay, and unknown payers keep the codes as billable lines by default.

The `qualifyingCircumstances.suppress` map controls this behavior per payer class, and the Medicare suppression is on by default. If your organization bills qualifying circumstance codes to all payers by contract, contact your Hank representative to turn the Medicare entry off before your next deploy. If a payer class you bill does not pay these codes (for example, some state Medicaid programs), your Hank representative can turn suppression on for that class only. The bundled entry then names that class.

## Why a 99100 did not bill

Read the entry in the bundled procedures. Its reason tells you which cause applied.

| What the bundled reason states | What happened |
|---|---|
| The payer class | Payer-class suppression moved the code. Read Payer classes above. |
| The age on the date of service, and the criteria it missed | The patient is not younger than 1 year and not at least 70 years and 1 day on the date of service. Confirm the date of birth and the date of service. |
| The anesthesia code 00326, 00561, 00834, or 00836 | CPT does not allow 99100 with that anesthesia code. Confirm the anesthesia code, then leave 99100 off. |
| That the age could not be verified | The record gave no usable date of birth, date of service, or documented age. Locate the missing value, then reprocess the claim. |
| That the add-on is reported once per anesthetic | A second 99100 line was a duplicate of the first. The first line bills. |
| A confidence below the 11 percent threshold | The autocoder removes a low-confidence 99100 or 99140 on any payer. Confirm the age or emergency basis is documented. This threshold is not configurable. |

No entry in the bundled procedures and no alert means the code was never coded. Confirm the qualifying basis is documented, then report it as a coding gap.

The `qc_config_fault` alert (FINANCIAL, severity 5) can appear beside any of these, and on a claim where 99100 did bill. It means the facility qualifying circumstance settings could not be read as written, so the autocoder applied a fallback posture. The alert names each fault and the posture it applied. Fix the configuration so the intended posture applies.

Every claim also records the payer class the autocoder resolved and the posture it applied, so a reviewer can see why a code was billed or withheld without guessing at the configuration.

## How this reaches you

What happens next depends on how your organization consumes HANK CODES. In HANK Claim Maker, a FINANCIAL alert flags the claim for the team your administrators configured for it, and a HARDSTOP alert places the claim in the review queue your administrators configured for it. Organizations that consume the coding API directly decide in their own workflow which alerts pause a claim, who reviews them, and when a claim is released.