Medicare pays for home health services, durable medical equipment, and other physician-ordered items only when the underlying physician order or physician certification satisfies specific timing, content, and signature requirements. When a Medicare contractor finds the order or certification late, incomplete, or improperly signed, it denies the claim even when the underlying care was medically appropriate. Because one physician's signature can appear on hundreds of orders across a hospital, home health agency, or equipment supplier, a pattern of certification defects can support a recoupment demand reaching back years once extrapolation is applied to a sample of claims. This article explains what a valid order or certification must contain, the deadlines Medicare enforces, and the defects that most often produce denials.
Background
Medicare's documentation standards for orders and certifications appear in the Medicare Program Integrity Manual (CMS Publication 100-08), which requires that the individual ordering or certifying an item be identifiable in the medical record and that every order carry a valid signature. A RAC or other postpayment contractor applies this manual when selecting claims for audit. The exposure is real: CMS reported a national Medicare fee-for-service improper payment rate of 6.55 percent, or $28.83 billion, for fiscal year 2025, with documentation deficiencies contributing significantly to that total.
What a Valid Certification Requires
For home health services, 42 CFR 424.22 conditions payment on a physician or allowed practitioner certifying five elements: intermittent skilled need, homebound status, an established and periodically reviewed plan of care, ongoing physician oversight, and a qualifying face-to-face encounter. The certification must be signed and dated by the certifying practitioner at the time the plan of care is established, or as soon after as possible. The face-to-face encounter must occur no more than 90 days before the start of care or within 30 days after it, and the certifying practitioner must document the encounter date.
For durable medical equipment and supplies (DMEPOS), CMS's standard written order rule requires six elements before a supplier may bill Medicare: the beneficiary's name or Medicare Beneficiary Identifier, an item description, the quantity if applicable, the order date, the treating practitioner's name or NPI, and the practitioner's signature. The order must reach the supplier before the claim is submitted; an order obtained afterward does not cure the defect. A local coverage determination issued by the DME Medicare Administrative Contractor may add further documentation requirements for specific items.
Common Certification Defects That Trigger Denials
Signature problems are the most frequent finding. The Medicare Program Integrity Manual, Chapter 3 requires a handwritten or valid electronic signature on every order and treats an unsigned order as void for medical review: the order is disregarded, and Medicare does not accept a retroactive order. A signature attestation statement can rehabilitate other missing signatures in the record, but CMS excludes orders from that remedy.
Late certification is a second common defect. A certification signed weeks or months after the plan of care was established, with no explanation for the delay, invites a contractor to question whether the physician reviewed the case before services began. A June 2025 OIG compliance audit of a home health agency found that 20 of 100 sampled claims failed to meet Medicare billing requirements, including four that did not satisfy plan of care requirements, contributing to an estimated overpayment of at least $100,696 for the audit period.
Missing or generic face-to-face documentation is a third defect: auditors deny claims when the encounter note does not tie to the primary reason the patient needs home health services, or when the certification omits the required encounter date. A denial on any of these grounds can be appealed through the process described in The Five Levels of Medicare Overpayment Appeals.
An unsigned, undated, or after-the-fact physician order gives a Medicare contractor grounds to deny the claim regardless of whether the underlying care was medically necessary.
Why Early Legal Counsel Is Critical
It is critical that physicians and other healthcare providers promptly retain experienced healthcare defense counsel upon receiving a subpoena, audit notice, additional documentation request, or other government inquiry concerning physician orders or certifications. Early legal intervention can protect the provider's rights, ensure appropriate responses to government requests, avoid inadvertent admissions, preserve relevant defenses, and allow counsel to communicate with investigators on the provider's behalf. Delaying legal representation can significantly affect the outcome of a matter and expose the provider to unnecessary risk.
How Health Law Alliance Can Help
Health Law Alliance represents physicians, home health agencies, and DMEPOS suppliers in Medicare audits where the sufficiency of a physician order or certification is at issue. The firm has handled 2,000+ audits across federal and state programs, including matters involving certification and signature defects, additional documentation requests, and appeals of unsupported denials. Physicians and providers facing a certification-related audit or denial may contact Health Law Alliance's Medicare audit defense team for a free, confidential consultation.
