> ## Documentation Index
> Fetch the complete documentation index at: https://mso.getlemma.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What billers actually do

> A day in the life across the revenue cycle: front end, middle, and back end, the coder/biller distinction, and the metrics that define a good one.

A **medical biller** is the person who converts delivered care into collected money: verifying coverage, entering charges, submitting claims, posting payments, working denials, and collecting patient balances. They are the connective tissue between clinical documentation and cash, and in a small practice they are the single highest-leverage non-clinical hire.

## The three phases of the revenue cycle

| Phase         | Activities                                                                                               | Who typically does it            |
| ------------- | -------------------------------------------------------------------------------------------------------- | -------------------------------- |
| **Front end** | Registration, insurance capture, eligibility verification, prior authorization, point-of-care collection | Front desk, sometimes the biller |
| **Middle**    | Charge capture, coding, charge entry, scrubbing, claim submission                                        | Clinician, coder, biller         |
| **Back end**  | Payment posting, denial management, appeals, AR follow-up, patient collections, refunds                  | Biller                           |

Most denials originate in the **front end** and are paid for in the **back end**. A biller who only works the back end is permanently cleaning up someone else's mistakes. The good ones push fixes upstream.

## A day in the life

**Morning.** Check overnight clearinghouse reports and work every 999 and 277CA rejection before anything else — they are the cheapest problems available and they expire. Then run eligibility on tomorrow's schedule and flag coverage problems for the front desk to call today.

**Midday.** Enter charges for yesterday's completed visits. Reconcile the schedule against charges so nothing was seen without a charge — the **unbilled encounter report** is the single most valuable daily number. Run the scrubber, clear the edits, submit the batch.

**Afternoon.** Post 835s. Auto-posting handles most lines; the exception queue gets a human — unmatched claims, PLB takebacks, interest, secondary transfers. Confirm every deposit ties to its remittance by TRN.

**Late afternoon.** Work the denial queue by CARC group. Corrected claims out, appeals drafted, root causes tagged. Then patient calls: statements, balances, payment plans, and the occasional refund.

**Weekly.** AR aging review. Credit balance report. Credentialing grid update. Follow-up calls on payer applications that have gone quiet.

## Coder vs biller

|                  | Coder                                               | Biller                                   |
| ---------------- | --------------------------------------------------- | ---------------------------------------- |
| **Job**          | Translate documentation into CPT/HCPCS/ICD-10       | Get claims out, money in, denials worked |
| **Skill**        | Clinical knowledge, coding guidelines, payer policy | Payer rules, systems, persistence        |
| **Credential**   | CPC (AAPC), CCS (AHIMA)                             | CPB (AAPC)                               |
| **In an MSO-PC** | Coding is a **PC** responsibility                   | Billers are typically **MSO** employees  |

In most small practices these are one person, and the clinician codes their own encounters. That is normal. What matters structurally is that the MSA is clear that **coding responsibility rests with the PC** — see [What an MSO can and can't do](/concepts/model/what-msos-can-and-cant-do).

## What separates a good biller from an adequate one

An adequate biller submits claims and posts payments. A good one:

**Works rejections same-day.** Not weekly. A rejection queue that ages is revenue quietly running toward timely filing limits.

**Tags root causes, not just fixes.** "Fixed and resubmitted" tells you nothing. "Authorization obtained but never entered into the PM field" tells you what to change.

**Pushes fixes upstream.** The best billers spend part of their time changing the front desk's workflow, because that is where the money actually leaks.

**Reads contracts.** Knows each payer's timely filing limit, appeal deadline, and contracted rates, and notices when a payment is short.

**Catches underpayments.** Compares allowed amounts against the contracted fee schedule. Systematic underpayment is invisible unless someone looks.

**Knows the difference between a rejection and a denial.** And doesn't waste appeals on claims that were never adjudicated.

**Escalates well.** Knows when to call provider relations, when to invoke a prompt-pay statute, and when a claim needs a supervisor rather than another portal submission.

## The metrics a biller owns

| Metric              | Definition                                     | Target       |
| ------------------- | ---------------------------------------------- | ------------ |
| Clean claim rate    | Accepted on first submission ÷ submitted       | 95%+         |
| Days in AR          | AR ÷ average daily charges                     | Under 40     |
| Denial rate         | Lines denied ÷ lines adjudicated               | Under 5–10%  |
| Net collection rate | Payments ÷ (charges − contractual adjustments) | 95%+         |
| AR over 90 days     | % of AR aged 90+                               | Under 15–20% |
| Unbilled encounters | Visits with no charge                          | 0            |

**Net collection rate** is the one that catches quiet leakage. A practice can have an excellent clean claim rate and still be at 88% net collection because it writes off patient balances, misses timely filing, or never appeals underpayments.

## How many billers do you need

Highly specialty-dependent — a high-volume, low-complexity practice generates far more claims per clinician than a surgical one.

Directional heuristics:

| Setting                            | Rough ratio                      |
| ---------------------------------- | -------------------------------- |
| Primary care, behavioral health    | \~1 biller per 4–8 clinicians    |
| Specialty with moderate complexity | \~1 per 3–5 clinicians           |
| Surgical, high-complexity          | \~1 per 2–4 clinicians           |
| High-volume PT/chiro               | Volume-driven; often \~1 per 3–5 |

Better than any ratio: **measure the work.** If claims go out same-day, rejections are worked same-day, the denial queue has nothing over 14 days, and AR is stable, you have enough billers. If any of those slips, you don't.

## In-house vs outsourced

The honest general answer: **below roughly two full-time clinicians, an outsourced RCM service usually costs less than a competent full-time biller.** Above that, in-house buys visibility and control that percentage-of-collections pricing does not.

The hybrid — in-house front end, outsourced denials and AR follow-up — works well for groups that want control over the prevention side while buying scale on the recovery side.

See [In-house billing vs outsourced RCM](/guides/billing/in-house-vs-outsourced-billing) and [Hire your first biller](/guides/billing/hire-a-biller).

## An interview exercise that works

Hand the candidate a redacted 835 with a CO-45, a PR-2, a CO-197 denial, and a PLB takeback in it, and ask them to walk you through it.

You are listening for: do they distinguish CO from PR correctly? Do they recognize CO-45 as normal rather than a problem? Do they know a CO-197 can't be billed to the patient? Do they notice the PLB and understand why the deposit won't match the claim total?

A candidate who handles that conversation fluently can do the job. One who cannot will cost you more than their salary.


## Related topics

- [The life of a claim](/concepts/payments/claim-lifecycle.md)
- [Claim denials, explained](/concepts/payments/claim-denials.md)
- [Clearinghouse vs RCM vs EHR (vs biller)](/concepts/payments/clearinghouse-vs-rcm-vs-ehr.md)
- [Hire your first biller](/guides/billing/hire-a-biller.md)
- [Work the denial queue](/guides/billing/work-the-denial-queue.md)
- [Decide: in-house billing vs outsourced RCM](/guides/billing/in-house-vs-outsourced-billing.md)
- [CARC codes (Claim Adjustment Reason Codes)](/reference/edi/carc-codes.md)
- [Denial code playbook](/reference/edi/denial-code-playbook.md)