30-Day Payment Period
The 30-day payment period is the unit of payment for Medicare home health under the Patient-Driven Groupings Model (PDGM). Each period is independently classified into one of 432 case-mix groups and billed on its own claim, with two payment periods fitting inside each 60-day certification period.
How 30-day periods fit inside 60-day certifications
PDGM changed the payment unit, not the clinical cycle. The physician or allowed practitioner still certifies a 60-day period of care, the comprehensive assessment still follows the Start of Care and recertification schedule, and OASIS is not redone every 30 days. Each 60-day certification simply contains two back-to-back payment periods. The second period begins on day 31 with no new assessment required, though the claim for it is built and adjudicated separately. If care continues past day 60, a recertification assessment opens the next certification period and the next pair of payment periods.
Each period is classified on its own
Every 30-day period gets its own case-mix group and its own payment. The variables can shift between periods within the same certification. Timing is the most predictable change: the first period in a sequence is early, and every subsequent adjacent period is late, which carries a lower weight. Admission source can change if an inpatient stay occurs close to the start of a later period. Diagnoses can be updated if the patient's condition changes and the record supports it. Functional impairment level generally carries from the most recent OASIS assessment, so it updates at recertification or resumption of care rather than at the 30-day mark.
Billing mechanics per period
A single Notice of Admission (NOA) covers the entire admission, so it is filed once, within 5 calendar days of the Start of Care. After that, each 30-day period is billed on its own final claim once the period ends and services are documented. Claims must process in sequence, so a problem on one period's claim holds every claim behind it. A gap of 60 or more days without home health resets the sequence, which means the next admission starts a new early period and requires a new NOA.
Common pitfalls
The second period of a certification is where avoidable revenue loss concentrates. Watch for these patterns:
- Visit frequencies taper in the back half of the certification and the second period falls below its LUPA threshold
- Missed visits near the end of a period are never rescheduled, converting a full payment to per-visit payment
- Teams assume timing is early because the patient is new to the agency, when Medicare's records show recent home health elsewhere
- Discharges and transfers mid-period trigger partial episode payment proration that nobody modeled
Period-level visibility, not episode-level averages, is what catches these.
Frequently asked questions
Do I need a new OASIS assessment every 30 days?
No. OASIS follows the 60-day certification cycle and specific events like resumption of care, transfer, and discharge. The 30-day period is a billing construct, and the second period of a certification typically draws on the same assessment as the first.
Can the first period pay in full and the second become a LUPA?
Yes, and it is common. Each period's visit count is measured against its own LUPA threshold. A typical pattern is adequate visits in period one, then tapering frequencies in period two that drop the count below the threshold and convert the period to per-visit payment.
When does a new 30-day period start?
Day 31 of the admission, immediately after the prior period ends, for as long as care continues. There is no new assessment or NOA at the boundary. A break of 60 or more days without home health care ends the sequence, and a subsequent admission starts a new early period.