Shrinking retroactive coverage means late Medicaid applications will leave more early dementia testing bills unpaid. Retroactive coverage is backdated Medicaid payment for covered care received before approval, and that window shrinks in 2027.
Traditionally, states paid covered bills from up to 3 months before the application month, according to the Congressional Research Service report. For applications after Dec. 31, 2026, the window falls to 1 month for expansion adults and 2 months for others, according to the ContentLora explainer on the 2025 reconciliation law.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- What is shrinking?
- Why does timing hurt a new dementia workup?
- Which new tests fall into the gap?
- What can families do before applying?
What is shrinking?
Retroactive eligibility protects people who need care before paperwork is finished. A person sees a doctor, gets tests, then applies for Medicaid. If approved, Medicaid pays back for covered bills in the protected months before the application month.
That protection is already thinner in some states. Florida, Iowa and Tennessee eliminated retroactive eligibility through Section 1115 waivers, while Arizona limited it for most adults, according to the KFF 50-state survey of seniors and people with disabilities. The 2025 reconciliation law makes a shorter window national policy for later applications.
Why does timing hurt a new dementia workup?
Confusion often starts slowly. Families watch, schedule primary care, wait for referrals, then face memory testing. Each step creates a bill with its own date.
A person with new confusion who delays applying may leave 1 to 2 months of evaluation bills outside the shorter 2027 window, according to the Medicare Rights Center analysis. Those bills become patient debt or hospital uncompensated care rather than covered diagnosis costs. The Alzheimer's Association says early diagnosis at mild cognitive impairment enables care planning, trial access and treatment decisions.
Which new tests fall into the gap?
Blood testing has made early evaluation simpler. The FDA cleared the Lumipulse G pTau217/B-Amyloid 1-42 plasma-ratio test on May 16, 2025 for adults 55 and older with cognitive signs, according to the FDA approval notice. It offers a less invasive alternative to PET or spinal tap.
Payment has not kept pace. A review of all 51 Medicaid programs found only 18 mention Alzheimer's blood tests and fewer than half list billing codes, according to KevinMD physician reporting from August 2025. For amyloid PET, CMS retired national coverage determination 220.6.20 effective Oct. 13, 2023, ending coverage-with-evidence-development and the once-per-lifetime limit and leaving decisions to regional contractors.
What can families do before applying?
Apply soon after new memory symptoms prompt medical care. The application date sets the backward window. Earlier filing keeps more evaluation weeks inside coverage.
Keep a dated record from the first visit onward. Save visit summaries, test orders, lab receipts and hospital bills. Ask the billing office whether each evaluation service is a covered benefit under your state program. Save every evaluation receipt with its service date and code.
- file the Medicaid application promptly after the first evaluation visit
- list symptom start, visit dates and every test ordered
- ask the clinic what billing code each blood test or scan will use
- keep copies of bills that arrive before approval
