Medicare's 100-Day Skilled Nursing Benefit: What San Diego Families Get Wrong

By Marcus Reyes, LSW · July 20, 2026

The three-day rule — and the observation-status trap

Original Medicare will only pay for a skilled nursing facility (SNF) stay if it follows a qualifying inpatient hospital stay of at least three consecutive days, not counting the day of discharge. That single sentence causes more surprise bills for San Diego families than almost anything else in senior care.

The trap is that a hospital can keep a patient for three nights under 'observation status' — an outpatient designation — and those nights do not count toward the three-day rule. A parent can spend four days in a bed at Scripps Mercy, Sharp Grossmont, or UC San Diego Health, be transferred to rehab, and then learn Medicare is paying nothing. Hospitals are required to give you a Medicare Outpatient Observation Notice (MOON) within 36 hours if you are under observation. Read it, and ask the case manager directly: 'Is my parent admitted as an inpatient, or under observation?' Ask on day one, not at discharge.

Medicare Advantage plans work differently. Many waive the three-day rule entirely, but nearly all require prior authorization before the SNF stay begins — and they can deny or shorten it. If your parent has an Advantage plan, the plan's approval, not the hospital's judgment, controls the coverage.

What Medicare actually pays, day by day

The '100 days' figure is real but widely misunderstood. Days 1 through 20 of a qualifying SNF stay are covered in full, with no coinsurance. Days 21 through 100 carry a daily coinsurance that Medicare resets every January — check the current figure at medicare.gov or with a counselor before you budget for it. After day 100, Medicare pays nothing for that benefit period.

Just as important: 100 days is a ceiling, not an entitlement. Coverage continues only while your parent needs and is receiving daily skilled care and the facility documents it. In practice, most San Diego rehab stays end well before day 100 — two to four weeks is far more typical. Families who plan around the full 100 days are the ones caught short.

The 100 days reset only when a new benefit period begins, which requires 60 consecutive days out of a hospital and out of a SNF.

Choosing a San Diego skilled nursing facility

A key licensing distinction matters here. Skilled nursing facilities in California are licensed and inspected by the California Department of Public Health (CDPH) Licensing and Certification program — not by Community Care Licensing (ccld.dss.ca.gov), which oversees the RCFEs and board-and-care homes most families think of as assisted living. If you search the CCLD database for a SNF, you will not find it.

Use Medicare's Care Compare tool at medicare.gov/care-compare to pull star ratings, staffing levels, and inspection results for every certified SNF in San Diego County. Weight the staffing rating and the health-inspection rating more heavily than the overall star, and read the actual deficiency narratives rather than stopping at the number.

Expect pressure. A hospital discharge planner may hand you a list and ask for a decision the same afternoon. You are entitled to choose any facility with an available bed that accepts your parent's coverage, including one closer to family in North County or the South Bay rather than whichever facility has the fastest opening.

When coverage ends sooner than you expected

Before Medicare-covered days stop, the SNF must give you a written Notice of Medicare Non-Coverage, generally at least two days before the last covered day. That notice is not the end of the conversation — it triggers a fast-track appeal right.

You can request an expedited review by the Beneficiary and Family Centered Care Quality Improvement Organization (BFCC-QIO) for California; the phone number is printed on the notice itself. Call by the deadline stated on the form. While the review is pending, your parent generally stays in the facility without being charged for the disputed days. Appeals are frequently successful when therapy notes still show measurable progress or an ongoing skilled need.

Do not accept 'your parent has plateaued' as an automatic disqualifier. Medicare coverage does not require improvement — skilled care needed to maintain function or prevent decline can also qualify.

Planning for what comes after rehab

Start the after-rehab conversation in week one, not the week coverage ends. The realistic options in San Diego County are returning home with in-home help, moving to an RCFE or board-and-care, or long-term skilled nursing paid privately or through Medi-Cal. Each has a different lead time, and the SNF social worker will not manage that transition for you.

San Diego County's Aging & Independence Services can connect families to in-home support, IHSS screening, and caregiver resources at 800-339-4661. For free, unbiased help decoding a Medicare denial, an Advantage plan authorization, or a coinsurance bill, California's HICAP counseling program is available at 1-800-434-0222. Veterans should also ask the VA San Diego Healthcare System in La Jolla about community nursing home care and Aid & Attendance, which can run alongside these options.

Talk to a free San Diego advisor →

Common questions

Does Medicare pay for 100 days of nursing home care?

Not automatically. Medicare covers up to 100 days per benefit period, but only after a qualifying three-day inpatient hospital stay and only while daily skilled care is medically necessary and documented. Days 1–20 are fully covered; days 21–100 carry a daily coinsurance. Most stays end well before day 100.

Do observation days count toward the three-day hospital requirement?

No. Nights spent under observation status are billed as outpatient care and do not count toward the three-day inpatient requirement under Original Medicare. Ask the hospital case manager on day one whether your parent is admitted as an inpatient, and read the Medicare Outpatient Observation Notice you are given.

Can I appeal when the rehab facility says Medicare coverage is ending?

Yes. The facility must give you a Notice of Medicare Non-Coverage, usually two days before the last covered day, and it lists the phone number for an expedited BFCC-QIO review. Call by the deadline on the notice. Your parent generally is not charged for the disputed days while the review is pending.

Are skilled nursing facilities listed in the CCLD database?

No. California skilled nursing facilities are licensed by the California Department of Public Health, while ccld.dss.ca.gov covers RCFEs, assisted living, and board-and-care homes. Use medicare.gov/care-compare for SNF ratings and inspection results in San Diego County.