Judgment was reserved in a High Court challenge to the legal definition of a terminal illness.
Lorraine Cox, a Co Fermanagh woman with Motor Neurone Disease, claims she was wrongly denied fast-tracked disability benefit because of uncertainty over how long she has left to live.
The mother-of-three's lawyers allege discrimination in a rule that those qualifying for the payments are expected to die within six months.
Following a two-day hearing Mr Justice McAlinden pledged to rule on the case as soon as possible.
"Obviously it's a matter I will have to give careful consideration to," he said.
"I will deliver my judgment in due course."
Ms Cox, 40, and from Derrylin, is seeking to judicially review the Department for Work and Pensions at Westminster, and Stormont's Department for Communities.
In 2018 she was formally diagnosed with Motor Neurone Disease (MND), a fatal condition affecting the brain and nerves.
Having retired on medical grounds, she applied for Personal Independent Payments (PIP) to help with the impact of the disease.
Under special rules claimants with a terminal illness are entitled to an enhanced rate without having to undergo assessment.
However, Ms Cox was initially awarded the standard rate.
It took more than a year of tribunals, appeals and face-to-face assessments before she qualified for the increased payments.
Her legal team claim she also had to spend months searching for work as part of attempts to secure Universal Credit (UC).
That was despite providing medical confirmation of her MND with a prognosis of between two and five years, the court heard.
Proceedings centre on an eligibility for higher rates of PIP and UC based on an expectation of dying within six months.
The rule breached the human rights of a woman whose illness is undoubtedly terminal but has an "unpredictably trajectory", counsel for Ms Cox argued.
Even though some with the disease may die inside six months, a definitive prognosis is impossible.
Meanwhile, those suffering from other terminal conditions with greater certainty about when they will die have their benefit claims fast-tracked without having to "go through all the hoops", she contended.
Mr Justice McAlinden must now determine whether the alleged difference in treatment amounts to unlawful discrimination.