Pillar guide · Updated May 2026

The 2026 medical billing guide for U.S. practices.

Everything that happens between a patient walking in and money landing in your bank account: coding, eligibility, claim submission, denials, A/R, and the KPIs that separate practices that get paid from those that don't.

11 sections Updated quarterly Print-friendly
Medical biller reviewing claim submissions and revenue cycle dashboards
Section 1 · The basics

What medical billing actually is.

Medical billing is the operational pipeline that translates a clinical encounter into paid revenue. Every patient visit triggers a sequence: verify coverage, document care, code procedures and diagnoses, submit a claim, post payment, transfer balance to the patient, follow up on denials. Each step has rules, deadlines, and failure modes. When billing works, your practice gets paid in 30 days. When it doesn't, your A/R aging report tells the story.

This guide walks the full pipeline. Each section links to a deeper page if you want the operational details. If a term is unfamiliar, the billing glossary defines 77 of the ones that matter.

Section 2 · The revenue cycle

Eight stages from scheduling to closed claim.

Healthy practices hit every stage on time. Aging A/R usually traces back to a stage that broke.

01

Patient registration and demographics

Capture full demographics, insurance card front and back, secondary coverage, and a current address. 70% of denials trace back to errors here.

02

Eligibility verification

Real-time check of active coverage, deductible status, copay, and OOP max before the visit. Skipping this stage is the cheapest way to lose revenue.

How verification works at MHB
03

Prior authorization

Payer pre-approval for services that require it (imaging, surgeries, certain meds, DME). No auth equals no payment, often unrecoverable.

04

Charge capture and coding

The clinical encounter becomes CPT, ICD-10, CDT, and HCPCS codes plus modifiers. Documentation must support every code billed.

Inside our coding workflow
05

Claim submission

The 837 EDI claim goes through a clearinghouse to the payer. Pre-submission scrubbing catches the avoidable errors.

End-to-end billing at MHB
06

Payment posting

ERAs auto-post; paper EOBs are scanned and posted within one business day. Variance reports flag underpayments against contracted fee schedules.

07

Patient billing

After insurance pays, the patient balance generates a statement with one-tap pay. Payment plans handle larger balances.

Patient payment processing
08

Denial management and A/R recovery

Denials get worked, appealed, escalated. Aged claims get triaged before timely filing closes. Root-cause feedback prevents repeat denials.

How A/R recovery works
Section 3 · Code sets

Three (sometimes four) code sets on every claim.

Every claim needs a procedure code (what was done), a diagnosis code (why it was done), and often modifiers (how it was done differently). Get any of them wrong and the claim denies.

CPT

Current Procedural Terminology

Outpatient and physician procedures, maintained by the AMA, updated annually. Five-digit codes that describe what was done.

ICD-10-CM

Diagnosis codes

Justify medical necessity. Codes are 3 to 7 characters. Specificity matters – vague codes cause denials.

CDT

Dental procedures

Maintained by the ADA. All codes start with D. Used for every dental claim.

HCPCS II

Drugs, transport, DME

J-codes for drugs administered in office, A-codes for transport, plus durable medical equipment and supplies.

Modifiers

How it was done differently

-25 (separate E/M), -59 (distinct procedure), -76 (repeat), -95 (telehealth), and dozens more.

Specialty deep dives: medical billing · dental billing · medical coding

Section 4 · Front-desk economics

Eligibility and prior auth decide whether the claim ever pays.

Eligibility verification is the cheapest, highest-leverage step in the whole cycle. A 60-second real-time check catches inactive plans, exhausted benefits, and prior auth requirements before the visit. Skipping it produces denial reasons CARC 22 (covered by another payer), CARC 27 (after termination), and CARC 197 (precertification absent), which together account for a meaningful share of all denials in most practices.

Prior auth has its own playbook: identify the requirement at scheduling, initiate the request, follow up daily, document the auth number with expiration, and chase recerts before expiration.

See how MHB handles eligibility & prior auth

Section 5 · Denials and A/R

Denials are signal. Work the signal.

Every denial has a CARC and often a RARC. The codes tell you what to fix. Recovering one claim is good; preventing the next 100 of the same denial type is better.

CARC 22, 27

Eligibility

Almost always preventable with real-time verification at check-in.

Preventable
CARC 197

Prior authorization

Preventable with auth tracking. Sometimes appealable when the service was urgent.

Mostly preventable
CARC 50

Medical necessity

Appealable with documentation, LCD/NCD reference, and clinical rationale.

Appealable
CARC 16, 96, 11

Coding / bundling

Often correctable. Bundling may need modifier -59 or an X-modifier.

Correctable
CARC 29

Timely filing

Usually unrecoverable. Monitor aging buckets so claims never sit this long.

Unrecoverable

A/R recovery & denial management

Section 6 · Provider enrollment

Credentialing is the precondition for getting paid.

Without active in-network status, claims either deny or pay at out-of-network rates. New providers need 60 to 120 days for full credentialing across major payers. Existing providers need re-credentialing every 36 months for most commercial payers, every 60 months for Medicare. Lapses pause cash flow.

The work involves CAQH ProView attestation every 120 days, Medicare PECOS forms (855I, 855B, 855R, 855O), state Medicaid enrollments, and per-payer commercial applications.

Provider credentialing at MHB

Section 7 · Measure what matters

The seven KPIs every practice should track monthly.

If your biller can't produce these numbers, they're not measuring – which means they're not managing.

96%+

Net Collection Rate

Payments / (charges - contractual adjustments - bad debt). The single best measure of revenue cycle health.

28–45 days

Days in A/R

How long money sits in A/R before being collected. Trending up means something broke upstream.

90%+

First-Pass Resolution Rate

Percent of claims paid on first submission with no further work. Below 90% means scrubbing or eligibility is leaking.

< 5%

Denial Rate

Percent of claims denied. Track total rate and top CARC reasons by payer.

95%+

Clean Claim Rate

Claims that pass scrubbing and reach the payer error-free. Closely related to first-pass.

70%+ in 0–30

Aging Bucket Mix

How A/R is distributed across 0–30, 31–60, 61–90, 91–180, 181+ buckets.

< 3 days

Charge Lag

Days from date of service to charge entry. Long lag means long delay before claim leaves the building.

Section 8 · Specialty matters

The same revenue cycle, different gotchas.

The eight stages apply everywhere, but the failure modes shift by specialty.

Section 9 · Operating model

In-house vs outsourced billing.

The honest math, not the sales pitch.

In-house

  • $55K–$85K/yr fully loaded per biller, plus PTO, sick, training
  • 2 billers for a 5- to 8-provider practice; 3+ at 10+ providers
  • $65K–$95K/yr for a certified coder if clinicians don't code
  • $400–$1,200/mo for PM/clearinghouse software
  • Re-hire risk every time a biller leaves; 60- to 90-day ramp-up

Math works when volume is large and stable enough to justify two or more dedicated FTEs and you have a manager who can supervise them.

Outsourced

  • 4–9% of collections (volume- and specialty-dependent)
  • No payroll variance, no PTO coverage, no re-hire risk
  • Certified coders included as part of standard scope
  • Software included, no additional licensing
  • Performance-aligned: they make more only when you collect more

Math works when collections variance, hiring difficulty, or denial volume make in-house unstable.

The honest version: most practices under $5M in collections do better outsourcing. Most over $20M can do either. The middle is judgment-dependent.

Section 10 · Choose carefully

Eight questions to ask any billing partner.

If they can't answer any of these directly, keep shopping.

1

What's your guaranteed turnaround on charge entry and claim submission?

2

Show me a recent client's monthly KPI dashboard – net collection rate, days in A/R, denial rate.

3

Who actually works my account? Names, titles, certifications.

4

What's your appeal-success rate on denied claims, and how do you measure it?

5

If we end the relationship, what's the data handoff process? Do we keep our A/R?

6

Are charges based on collections or submitted? (Submitted-based fees can hide write-offs.)

7

What's your BAA, security posture, and breach notification policy?

8

Will you train my front desk on eligibility, charge capture, and patient collections?

Pillar guide FAQ

Common questions about medical billing in 2026

Direct answers to what practice owners ask most.

How long should it take to get paid by Medicare?

Electronic Medicare Part B claims pay in 14 days on average, with a 14-day floor mandated by CMS. Paper claims take 29 days. If your Medicare claims are aging past 30 days, the issue is usually a kickout (NCCI edit, modifier, or missing PECOS enrollment) rather than payer slowness.

What's the difference between billing and coding?

Coding is the act of translating clinical documentation into CPT, ICD-10, CDT, and HCPCS codes plus modifiers. Billing is the operational pipeline that uses those codes to generate, submit, and follow up on claims. Some practices have one team; others split them. We staff certified coders (CPC, CCS, CPMA) separately from billing operations.

How do I know if my biller is doing a good job?

Ask for last month's net collection rate (target 96%+), days in A/R (target 28 to 45 depending on specialty), denial rate (target under 5%), and aging bucket mix (70%+ should be in 0 to 30 days). If they can't produce those numbers, they're not measuring – which means they're not managing.

Is outsourcing more expensive than in-house?

Depends on volume and stability. A 4-provider primary care practice doing $1.2M in collections typically spends $130K to $180K fully loaded on two in-house billers plus a coder and software. Outsourcing the same practice at 6% of collections is $72K. The math flips at higher volume with stable hiring. Below $5M in collections, outsourcing usually wins on cost and stability.

What happens if my biller misses a timely-filing deadline?

Most claims past timely filing are unrecoverable absent a specific exception (provider error, payer error, retroactive eligibility, COB confusion). The lost revenue should not show up on your bill from a percentage-of-collections billing partner; if it does, that's a contract you should renegotiate or exit.

How does the No Surprises Act affect my billing?

For out-of-network emergency services and certain non-emergency services at in-network facilities, you can't balance bill the patient. Disputes with the payer go through federal IDR. For most outpatient practices, the practical impact is on patient communication (good-faith estimates for uninsured / self-pay) and on out-of-network providers in narrow disputes. We screen claims for NSA scope and route disputed payments through IDR when warranted.

How fast can MHB take over our billing?

Standard onboarding runs 2 to 4 weeks, depending on EHR/PM access and how clean current credentialing is. Aged A/R cleanup runs in parallel with new-claim work; we don't make you wait. Schedule a call to scope your transition.

Ready to talk specifics?

From guide to your practice's numbers.

Reading about KPIs is one thing. Seeing yours is another. Free billing audit takes 30 minutes and you walk away with your real net collection rate, denial rate, and aging mix – whether you sign with us or not.

Free, no-obligation

See what your practice is leaving on the table.

30-minute free billing audit. We'll surface the leaks (undercoding, denials never appealed, eligibility errors) and quantify the dollars you can recover this quarter.

What you get

  • A line-by-line review of your last 90 days of claims
  • Specialty benchmark on clean-claim ratio & days in A/R
  • A written estimate of recoverable revenue this quarter
  • Zero pressure. Zero commitment.