Last spring, Jennifer Blair, a 62-year-old aspiring therapist who lives in Denver, noticed the kind of changes in her breast tissue — rapid, abnormal growth on one side of her chest — that would frighten any woman and alarm any physician.

Blair didn’t have health insurance, but because she didn’t earn much money, she qualified for Colorado’s state-run Women’s Wellness Connection program, which funds free mammograms through Planned Parenthood and other health-care providers.

Or so she thought. Blair was born a male, undergoing gender-reassignment surgery a decade ago. But the Centers for Disease Control and Prevention, which pays for the mammogram program, requires clients getting free screenings to be “genetically female.”

Blair eventually was able to scrape together the $400 cost of the mammogram, which ruled out cancer. But she said the frustration and humiliation still linger.

“It was so patently discriminatory and wrong,” she said.

Right or wrong, Blair’s predicament is one that advocates say more and more transgender people are confronting.

“This is just one example of the minefield that health care can be for a transgender person,” said Shane Snowdon, director of the Human Rights Campaign’s Health & Aging Program (and before that, founding director of the Center for LGBT Health & Equity at the University of California San Francisco). “It’s very seldom that you don’t encounter some kind of problem accessing care.”

It’s a considerable conundrum, given the complicated medical issues many transgender people face. In Blair’s case, these include exposure to large amounts of estrogen, the side effects of which have been found to include an elevated risk of breast cancer and life-threatening blood clots.

Breast cancer in the transgender population, though rare, is probably significantly underreported, according to the American Cancer Society. Indeed, Susan G. Komen for the Cure, the most prominent breast cancer organization in the country, urges transgender people to immediately report “any change in the look and feel of a breast.”

Adding to the complexity, transgender people still require the same kinds of medical care as they did before gender reassignment — pap smears for genetic females, for example, and prostate exams for genetic males. Transgender men can still get breast cancer following mastectomy or ovarian cancer if they haven’t had their ovaries removed; transgender women can still get prostate cancer.

This can be hard for providers and insurers to wrap their heads around, according to advocates. Once transgender people go through reassignment surgery, their sex change is marked in their medical records, and insurers often don’t want to pay for tests and treatments pertaining to the sex that a patient used to be, advocates say. In fact, people fortunate enough to have insurance through their jobs frequently discover that the fine print of their coverage explicitly bars paying for cross-gender medications or care.

That’s what happened last spring, when Aetna initially denied coverage for a New Jersey transgender woman’s mammogram. The company later backed down and apologized.

“That’s very common,” said Ilona Turner, legal director at the Transgender Law Center in Oakland. Indeed, a 2010 Institute of Medicine report found that when medical providers were aware of a patient’s transgender status, the patient was significantly more likely to be harassed or denied care.

Perhaps more common for transgender people, however, is the situation Blair found herself in: without any insurance whatsoever. In her case, a heart condition made her uninsurable, she said; for others, being transgender can itself be considered a pre-existing condition. And for still others, the decision to undergo gender reassignment requires them to leave their job or risk being fired, either outcome robbing them of their insurance.

The result is that transgender people are much more likely to be poor — and in poor health. In Colorado, male-to-female transgender people are four times more likely to be impoverished than the general population, a 2011 survey found.

Blair is exactly the kind of person that Colorado’s WWC program should be helping, said her lawyer, Sarah Parady, who has filed complaints with the state’s Civil Rights Division and the U.S. Department of Health and Human Services, which includes the CDC.

The Colorado Anti-Discrimination Act specifically bars discrimination against transgender people in places of “public accommodation” such as a health clinic, Parady said. Whatever the CDC says, “that does not excuse the WWC program from complying with Colorado law,” Parady said. She also noted under the CDC’s interpretation, male-to-female transgender people don’t qualify for free screenings — but female-to-male transgender people do. She called that distinction “inexplicable.”

In its written response to the complaint, the state Department of Public Health and Environment, which runs the WWC program, said it was bound by the CDC rule.

Meanwhile, Jacqueline Miller, the medical director overseeing the screening program for the CDC, has said the agency was only complying with a 1990 statute, the Breast and Cervical Cancer Mortality Prevention Act. “CDC’s position has been that federal funds can only be used to screen clients born as women since the law establishing the program specifically states women,” Miller said in an email to Colorado officials in July. To avoid denying necessary care, Miller added, the CDC encourages grantees “to identify other payment sources... that are not restricted to women.”

Now the Human Rights Campaign and the National Center for Transgender Equality have entered the fray. Last week, the groups sent a letter to the CDC’s director, Thomas Frieden, urging him to bring the agency’s interpretation into compliance with Affordable Care Act guidelines that prohibit discrimination on the basis of gender identity or sex stereotyping.

The CDC policy “is clearly discriminatory, dangerous to the health of an at-risk population, inconsistent with prevailing recommendations for transgender health care and at odds with current federal policy ensuring access to care for transgender individuals,” the letter said.

On the phone, Snowdon of the Human Right Campaign was even blunter, saying that the CDC rule “runs afoul of all contemporary medical thinking.”

In an email, a CDC spokeswoman said the agency is reviewing the letter and will respond “as soon as possible.”