Reviewed September 2026.
Open enrollment generally locks your plan choice for the year on most employer and Marketplace plans (Open enrollment). Participating providers can still change mid-year, so verify again before care. Checking providers after you enroll is how families discover a preferred pediatrician or hospital is out of network. HMO/PPO/EPO rules: Health insurance networks.
Build a must-keep list first
Write down, before you open any directory:
- Primary care clinician (PCP)
- Pediatrician / OB-GYN / main specialists
- Preferred hospital and nearest ER you would actually use
- Behavioral health clinician if ongoing
- Infusion, dialysis, or other facility-based care if relevant
Search each name on each plan you are considering (UnitedHealthcare, Anthem, Aetna, Cigna, Kaiser, BCBS affiliates, and Marketplace issuers all use separate directories).
Verify the right entities
| Check | Why it matters |
|---|---|
| Clinician NPI / exact practice name | Same doctor name can appear under multiple tax IDs |
| Facility (hospital or ASC) | Hospital in-network ≠ every doctor who bills there |
| Anesthesiology / radiology groups | Common surprise gaps on surgery days |
| Effective date of network status | Directories lag; call the billing office the week of enrollment |
A referral to an out-of-network specialist is its own problem (Out-of-network referral). Out-of-network bills: Out-of-network medical bills.
Worked example: two employer options
Priya must keep Dr. Nguyen (dermatology) and City General Hospital.
| Plan H (HMO) | Plan P (PPO) | |
|---|---|---|
| Directory: Dr. Nguyen | Not listed | Listed in-network |
| Directory: City General | Listed | Listed |
| PCP referral needed for derm | Yes | No |
Priya either (a) picks Plan P and accepts the higher premium, or (b) picks Plan H and switches to an in-network dermatologist. Do not assume a “guest” or one-off exception; if the insurer offers a written exception, it must name the provider, services, dates, and patient cost-sharing before you rely on it. Decision framework when flexibility is the issue: Switch from an HMO to a PPO.
Call script (5 minutes per provider)
“Hi, I’m comparing plans for coverage starting [date]. Is [clinician name], NPI [if known], participating at [location] for [exact plan/product name and group/metal level if Marketplace]? What is the network or product name on your contract, and is there a separate cost-sharing tier for this clinician?”
HMO/PPO/EPO are plan types, not directory “tiers.” Get the answer in writing or a portal screenshot. Re-check the insurer’s directory the same day. If the office and directory disagree, get insurer confirmation for that exact plan. Do not stop after a second office call.
Checklist
- List must-keep clinicians and facilities before shopping premiums.
- Search each plan’s live directory; do not trust last year’s card.
- Confirm facility and key clinician groups separately for surgeries.
- Screenshot directory results with date stamps.
- When directory and office disagree, get insurer confirmation for that exact plan (then save it).
- Only then compare deductibles and premiums (Deductibles).
Educational only. Not insurance advice. Directories and contracts change; confirm with the plan and provider before care.