From age 60 – or age 50 for the disabled – a survivor can either apply for a deceased spouse’s Social Security benefits (if these are greater than the survivor’s, or if the survivor has no background to be eligible) or apply temporarily and delay application on their own (allowing their benefit to increase until they reach full retirement age or beyond).

“Surviving spouses can end up with a lot more income,” said Trinh Phan, senior attorney at Justice in Aging. The average survivor benefit, reports the Social Security Administration, is $1,467 per month.

Ms. Thornton, for example, has always worked for nonprofits — first a food co-op, then a theater — and never earned as much as Ms. Brown, a staff member and teacher at Evergreen State College .

Alone, Ms. Thornton had to apply for Social Security early, at age 62, and turned to pet sitting to supplement her $953-a-month benefits. She lived modestly and did not often visit her family. “I couldn’t just buy a plane ticket and fly to California,” she said. “I had to put off my house maintenance for years.”

However, once Social Security started paying survivor benefits, her monthly income nearly doubled, to $1,849. And she received a lump sum of $72,000, a retroactive payment for the years the agency denied her request.

An unknown, and perhaps unknowable, number of people were never able to marry their late same-sex partners. But a second group has also become eligible for survivors’ benefits: same-sex couples married for less than nine months, the legal threshold for survivors’ benefits, before the death of one of the spouses.

Anthony Gonzalez and his partner, Mark Johnson, lived together in Albuquerque, NM, for nearly 16 years, thinking they could never get married in their state.